land application of accumulated solids from liquid waste ... application report.pdf · land...

Final Report

Land Application of Accumulated Solids

From Liquid Waste Systems

Demonstration Project

E.P.A. 319(h) FY 1997 Project 700

Prepared and Submitted by the

Arkansas Department of Environmental Quality

Environmental Preservation Division

September 30, 2002

draft

3

Table of Contents I. Introduction ................................................................................................................................. 9

II. Background .............................................................................................................................. 11

III. Land Application Project Description and Implementation ................................................... 17

Pond Clean-Out and Land Application Planning...................................................................... 19

IV. Solids Clean-Out Plan Development Strategy ........................................................................ 21

Liquid Manure Characterization ............................................................................................... 21

Waste Management Plan Review ............................................................................................. 23

Plan Development ..................................................................................................................... 23

V. Project Results.......................................................................................................................... 27

Returning to Facilities After Clean-Out .................................................................................... 34

Analysis of manure samples ..................................................................................................... 34

VI. Clean-Out Case Study............................................................................................................. 37

Tank Spreader Sampling ........................................................................................................... 41

VII. Aluminum Chloride Demonstration and Economic Alternatives ......................................... 43

University of Arkansas Report on Alum Addition ................................................................... 44

VIII Conclusions ........................................................................................................................... 55

References ..................................................................................................................................... 59

List of Appendix

Appendix A. Power Point Presentation Slides Presented to Regulation No. 5 Attendees and to

Participating Conservation Districts

Appendix B. LAWMS Sampling Procedures and Sampling Data Collection Sheet

Appendix C. LAWMS Clean-Out Plan Check List

Appendix D. Manure Management Services

Appendix E. Clean-Out Plan Summary

Appendix F. Raw Data From Sample Analysis

Appendix G. Example of a Completed LAWMS Clean-Out Plan

draft

5

Table of Figures Figure 1. Typical Concentrations of Nutrients in Maintained and Non-Maintained LAWMS ... 12

Figure 2. Locations of Swine Facilities in Arkansas ................................................................... 14

Figure 3. Nutrient Concentration Differences in Maintained and Non-Maintained LAWMS .... 15

Figure 4. Collection of LAWMS Pond Samples ......................................................................... 21

Figure 5. LAWMS Pond Sample Collection Methodology ......................................................... 22

Figure 6. High STP Adjacent to Facility ..................................................................................... 24

Figure 7. Locations of Participating Facilities ............................................................................. 27

Figure 8. Nutrient Concentrations in Holding Ponds Prior to and Following Annual Manure

Solids Removal ......................................................................................................................... 34

Figure 9. Concentration of Nutrients Found in Various Phases of LAWMS Manure Storage ... 34

Figure 10. Concentration of Analytes in Composite Samples Collected From Holding Ponds .. 35

Figure 11. Concentration of Analytes in Accumulated Manure Solids Samples Collected From

Holding Ponds……………………………………… ....................………………………...…30

Figure 12. Comparison of Nutrient Concentrations From Various Clean-Out Planning Data

Sources ..................................................................................................................................... 38

Figure 13. Houle "AgiSprayer" Equipment Used For Agitation During Pond Clean-Out

Process .................................................................................................................................. 39

Figure 14. Comparison of Composite Sample Results to Samples Collected From Land

Application Equipment ............................................................................................................. 40

Figure 15. Nutrient Concentration Change in Samples collected From Tank Spreader During

Clean-Out at Case-Study Facility ............................................................................................. 41

Figure 16. Nutrient Concentration Change in Samples Collected From Tank Spreader During

Clean-out at a Second Participating Facility……………………………………………… .....37

Figure 17. Addition of Aluminum Chloride to Holding Pond……….………………………….43

List of Tables Table 1. Numbers of Swine Facilities by Conservation District (1999) ....................................... 18

Table 2. Plan Development and Clean-outs by County ............................................................... 27

Table 3. LAWMS Characteristics of Project Facilities ............................................................... 29

Table 4. Available Acreage and Land Application Acreage Requirements for Participating

Project Facilities ....................................................................................................................... 30

Table 5. Summary of Land Application Planning and Clean-Out Status .................................... 31

draft

7

The Land Application Project team:

Sandi Formica, Project Manager

Matthew Van Eps, Project Engineer

Tony Morris, Resource Specialist

Jason Beck, Ecologist

William McRee Anderson, Ecologist

The project team appreciates the courtesy and cooperation of all individuals and entities that

helped the team with the execution of the project, including:

ADEQ Administrative Staff

Arkansas Soil and Water Conservation Commission

U.S. EPA Region VI

Arkansas Pork Producer Association

Cossatot Conservation District

Conway County Conservation District

Newton County Conservation District

Pope County Conservation District

University of Arkansas Department of Agronomy

Tyson Foods Pork Group

Cargill Pork

draft

9

I. Introduction

Arkansas has ranked 16th

in the United States in pork production over the past 10 years, yielding

570,000 hogs annually. Virtually all of the commercial production is from the approximately

400 confined swine facilities in the state that utilize permitted liquid waste systems to manage

the manure generated during the raising of swine. Storm water run-off from confined animal

production activities has the potential to contribute significantly to non-point source nutrient

loading to lakes and streams in the absence of adequate manure management practices. The U.S.

Environmental Protection Agency (EPA) reports agricultural activity as the leading source of

pollutants that threaten the water quality of rivers, streams, and lakes in the United States. Over

time, non-point sources of nutrients, sediment, pesticides, and biochemical oxygen demand can

render a body of water unable to support aquatic life, threatening entire ecosystems1. Non-point

source pollution, including nitrogen and phosphorus, from confined animal operations poses a

threat to water resources in the north-western half of Arkansas. Land application of the manure

generated from confined animal facilities has resulted in atypically high nitrate levels being

measured in surface and ground water2. Nutrients from confined animal facilities are also the

subject of litigation for watersheds in Oklahoma that drain from Northwest Arkansas. Efforts to

reduce the impacts of Arkansas’ confined animal industry on water resources, while keeping

production viable and sustainable for the industry, have been welcomed by government, industry

and swine producers. A Recent announcement indicating that many contracts will be terminated

at swine facilities in Arkansas does not diminish the importance of proper manure management,

and the work presented in this report will be applicable in addressing system closures in an

environmentally sensitive manner.

This report is a summary of a cooperative 3 year effort to protect water quality by improving

manure management at confined animal facilities having liquid animal waste management

systems (LAWMS). The project objectives were to:

$ Ensure the proper land application of manure from poorly maintained liquid waste

systems;

$ Assist cooperating farmers in recovering full liquid waste system storage

capacity;

$ Encourage better utilization of liquid waste derived nutrients, including a

reduction in the over application of phosphorous;

$ Encourage swine producers to recognize both the potential environmental hazards

and nutrient benefits of their liquid manure; and

$ Demonstrate manure utilization technologies that reduce the over application of

phosphorous from animal manure.

draft

10

The project goal, to protect and improve water quality in the state, was achieved through the

above objectives and by working directly with producers requesting assistance and Conservation

District Water Quality Technicians to develop farm specific clean-out plans based upon the

following factors:

1. Permitted land application acreage

2. Land application acreage cover crop

3. Mass of nitrogen (N) and phosphorous (P) in ponds based upon physical measurements

4. Soil test phosphorous levels in application site soils

5. Waste management equipment available to the farmer

draft

11

II. Background

Most confined swine facilities in Arkansas are small family owned farms that raise swine under

contract to large agribusinesses. The majority of these facilities were built during a period of

rapid industry growth in the 1980's. Liquid animal waste management systems (LAWMS) are

configured to store swine manure and waste water (rain and drinking water waste) in earthen

storage structures, utilizing recirculated water from storage to flush manure from the swine

barns. The storage structures are typically configured in a two-cell design consisting of a settling

basin, used to remove solids from suspension, and a holding pond, used for solids and waste

water storage. Recirculated water from the holding pond is released from 300 to 500 gallon

concrete flush tanks one or more times a day, to flush manure from the shallow concrete gutters,

which extend the length of the barns at a 2% grade. Settling basins are generally designed for 45

days of solids storage, and holding ponds are typically designed for a minimum of 120 days

storage of manure and waste water. The manure storage ponds are designed to be completely

emptied and the contents land applied at least twice per year.

Field observations and empirical data from the Buffalo River Swine Waste Demonstration

Project (Swine Project) revealed a number of common problems associated with improperly

maintained waste systems at swine production facilities in north-central Arkansas 3. Through

work conducted in the Swine Project it was noted that manure storage ponds at farms within the

Buffalo River Watershed were only occasionally, if ever, completely cleaned out prior to 1996.

Most farmers were observed to manage liquid levels in their storage structures by pumping from

the tops of the ponds with incomplete or no mechanical mixing of the contents. In addition, most

of the material removed from the ponds was generally applied to pastures that were the most

accessible relative to the barn complex. Farmers routinely maintained the minimum freeboard

levels in order to be in compliance with specific permit conditions and regulations; however,

ponds were not emptied for maximum nutrient utilization or storage capacity prior to the winter

months. Many farmers stated that if they completely emptied their ponds, they would then have

to use fresh water for flushing the barns until water levels in their ponds recovered to the point

where the flush pumps could be used. The problems associated with the operation and

maintenance of the LAWMS observed during the Swine Project resulted in the potential for

tremendous quantities of nutrients being transported to surface waters.

The Swine Project demonstrated that LAWMS that were not maintained resulted in solids

accumulating in the holding pond. With time, accumulated solids become increasingly difficult

to remove from LAWMS due to settling, biochemical breakdown and compaction. As solids

accumulate in manure storage ponds, there is less pond volume available for the required 120

days of storage, resulting in greater potential for pond discharges. The need to land apply at

inappropriate times, such as, the dormant season for the cover crop, to saturated or frozen soils,

or prior to or during storm events is also increased. Accumulation of manure solids in LAWMS

resulted in many producers having to spend more time than was anticipated on the operation of

their LAWMS in order to stay within some of the requirements of their permits.

draft

12

During the Swine Project, the

pond contents of LAWMS at

five participating farms were

extensively characterized to

determine nutrient and solids

concentrations. The results of

this work demonstrated that

pond contents are not uniform

mixtures, but are stratified. A

surficial gray water layer, with

relatively low concentrations of

solids and nutrients was found

on top of a solids layer having a

comparatively high

concentration of solids and

nutrients. The stratified pond

contents required considerable

mechanical effort during

agitation in order to arrive at a

homogeneous mixture that could

be pumped and evenly distributed onto application sites. Figure 1 compares typical nutrient

concentrations observed in samples collected at discreet intervals within maintained and non-

maintained swine farm holding ponds. If LAWMS holding ponds are routinely cleaned-out

(maintained) a more agronomically favorable nitrogen to phosphorus (N to P) ratio can exist in

the ponds. However, if a farmer merely land applies gray water in order to maintain the required

minimum freeboard levels (non-maintained), N is lost through ammonia volatilization and

microbiological activity while P accumulates, resulting in a more unfavorable N to P ratio. As an

example, the ratio of nitrogen and phosphorus uptake by bermuda and fescue grass is

approximately 10 to 1 (NRCS Agricultural Waste Management Field Handbook)4. In other

words, for every 10 pounds of nitrogen that a pasture of fescue assimilates, one pound of

phosphorus will be utilized. When fertilizer is applied to a crop it should be done in a manner in

which the requirements of the crop are met without over-applying nutrients. Manure storage

ponds that are not routinely maintained result in an unbalanced N to P ratio. Years of continued

solids accumulation will lead to a high concentration of nutrients, agronomically unbalanced N

to P ratios and an overall loss of storage volume in LAWMS.

A component of the Swine Project was developed to identify the effect that soil type has on

nutrient losses from fields receiving liquid manure applications. In that work, swine manure

slurry was land applied to test plots with identical slopes and vegetation and at the recommended

N based loading rate for a Tall Fescue cover crop. The test plots were then rained on at a

specified intensity and a known volume using rainfall simulation equipment. It was found that

the application of waste significantly increased nutrient concentrations in storm water runoff as

well as runoff volume. Depending upon soil type, 1.8 to 6.2% of total N, and 2.0 to 9.6% of total

P that was land applied was lost in storm water runoff from manure fertilized test plots5. This

work indicated that, even under controlled conditions, nutrient loss occurs through storm water

runoff following the land application of manure. In order to land apply liquid manure in a way

Figure 1. Typical Concentrations of Nutrients in Maintained and

Non-Maintained LAWMS

draft

13

that will result in the least amount of nutrients being transported to lakes and streams as non-

point source pollution every effort must be made to control the pertinent variables. Land

application variables can be best controlled by accurately estimating the nutrient load contained

within storage structures and then proceeding through a thoughtful, careful planning process in

which an easily followed course of action is outlined and implemented.

Another nutrient management related concern identified in the Swine Project was the build up of

phosphorus in the soil, generally described by soil test phosphorous (STP), on certain application

sites. STP concentrations in the soils of the most convenient fields for land application, typically,

those fields immediately adjacent to the LAWMS, commonly exceeded 300 pounds per acre.

This value exceeds the concentration considered by many professionals in the field of non-point

source pollution to be an upper cut off level for additional applications of the nutrient. Values

approaching or exceeding the upper limit of the Melich III test method are not uncommon in

areas with high densities of confined animal production facilities. The high STP issue created

additional difficulties when attempting to address solids and nutrient accumulation problems in

LAWMS. Pastures exceeding the 300 pounds per acre concentration could not be recommended

for land application of accumulated swine manure solids during the Swine Project.

Many of the problems observed during the Swine Project regarding the operation of LAWMS

could be attributed to, or exacerbated by, the geographic locations of the facilities. All of the

participating farms were constructed within hilly or mountainous terrain which greatly affected

all aspects of manure management activities. From controlling and excluding storm water, to

accessing holding ponds and land application sites located on steep hill sides with equipment,

farm locations created operational challenges for farmers. However, the terrain on which the

cooperating Swine Project farms were located was not unique to the Buffalo River watershed,

hillsides and hilltops are frequently the locations for confined animal facilities in Arkansas.

Questions were raised as to whether the accumulation of manure solids and associated nutrients

observed in the Swine Project was merely a localized phenomenon or were the issues noted with

LAWMS common throughout the swine industry in Arkansas.

In Arkansas, the swine production industry is concentrated in the north-western part of the state

(Figure 2). Farms are typically concentrated in a region to reduce integrator expense associated

with the transportation of animals and feed as well as to facilitate better oversight of the

production process. Few swine facilities are located in the Arkansas delta region where manure

derived nutrients could be readily utilized by grain or cotton crops. The scarcity of confined

animal facilities in Eastern and Southern Arkansas may be due to the land and time requirements

associated with the current agricultural economy of the “delta” region. In any event, most

confined animal operations are located in a portion of the state that is often hilly or mountainous

with soils that are not highly productive and cannot utilize a large mass of nutrients. The general

geographic location of the industry highlights the necessity for effective manure management.

As seen in Figure 2, most swine production is concentrated within a 40 mile radius of Dierks in

Howard County, Russellville in Pope County and Fayetteville in Washington County. From a

nutrient management perspective, it should be noted that the areas of high swine farm density

overlap areas of high poultry broiler farm density.

draft

14

Figure 2. Locations of Swine Facilities in Arkansas

Based upon solids accumulation related environmental concerns, the Environmental Preservation

Division of the ADEQ and the Arkansas Pork Producers Association cooperatively initiated the

State-Wide Pond Solids Survey 6. The goal of the Solids Study was to assess the extent of the

solids and nutrient accumulation problem within swine LAWMS throughout Arkansas. Over a

two month period in the fall of 1997, 10% of the approximately 400 swine farms in the state with

permitted liquid waste systems were randomly selected for pond sampling. Staff from the

Environmental Preservation Division visited the selected farms and collected representative

samples of the storage pond contents utilizing tools and methods developed during the Swine

Project. Also collected during this study was basic information about the LAWMS and operator

experience in running the systems. A significant finding of the Solids Study was that a majority

of the facilities had more manure solids in the holding ponds than should have been there based

on the waste system design. Generally, LAWMS in Arkansas are designed to have

approximately 20 percent of the pond volume occupied by accumulated solids prior to a clean-

out. The normal accumulations of solids are intended to be removed each year. Of the 40 waste

systems sampled, 35 systems had more than 20 percent of the design pond volume occupied with

accumulated manure solids. Furthermore, 24 of the facilities had more than 40 percent of the

draft

15

pond volume filled with manure solids. None of the producers had ever completely emptied the

contents of their LAWMS and only half of the facilities utilized some type of mechanical mixing

or agitation when pumping liquid manure from their systems.

Analysis of manure samples

collected from the storage

structures in the Solids Study

confirmed previous results from

the Swine Project. Ponds that

were not maintained, i.e. solids are

not removed annually, have much

higher nutrient concentrations.

Figure 3 illustrates the difference

of nutrient concentrations in

maintained and non-maintained

LAWMS. Non-maintained

systems with accumulated solids,

had concentrations of total N and

P that were greater than

maintained systems by 3.2 and 3.8

times respectively. Based upon the

observations of the Solids Study,

in order to clean-out a LAWMS that had not been maintained, the amount of land required to

assimilate the accumulated solids and associated nutrients would be 3 to 4 times that which

would be required if the systems were maintained.

An interesting finding from the Solids Study work involved the efficacy of agitation equipment

utilized for mechanical mixing of manure storage pond contents during land application.

Surprisingly, when the accumulated solids content of ponds from farms utilizing agitation

equipment was compared to farms without equipment, there was essentially no difference. This

indicated that farmers were unable to thoroughly mix the contents of their holding ponds and

remove manure solids at many facilities. This is likely due to equipment being inappropriately

sized or typed, insufficient access to all portions of the ponds, and/or underpowered or incorrect

use of equipment. The inefficiency of agitation equipment is not only another potential cause for

manure solids accumulation in swine LAWMS, it can also be a waste of time, money and effort

by the individual farmer.

The results of the Swine Project and the Solids Study indicated that the difficulty of managing

manure solids in LAWMS was a statewide occurrence in Arkansas. Accumulating solids in

manure storage ponds was causing producers to spend inordinate amounts of time with their

systems and generally, increased the potential for ponds to overflow and the need to land apply

liquid manure during times of the year that would result in large amounts nutrients reaching

surface waters. Results from these studies were presented to facility operators across the state to

inform them of the problems associated with accumulated manure solids. However, it was not in

the interest of protecting water quality to remove accumulated manure solids without a plan

specifically addressing the high concentration of nutrients. A planning system that could help

Figure 3. Nutrient Concentration Differences in Maintained and

Non-Maintained LAWMS

draft

16

swine facility operators address solids accumulation problems in an environmentally responsible

manner was needed.

draft

17

III. Land Application Project Description and Implementation

The results of the Swine Project and the Solids Survey indicated that accumulated manure solids

in LAWMS at swine facilities was a common occurrence throughout the swine industry in

Arkansas. Also apparent was that accumulated manure solids contained much higher nutrient

concentrations than would be indicated in the facility waste management plan. Although this

information was brought to the attention of both producers and the industry, the EPD did not

want to create a situation that would lead to multiple facilities within a single drainage basin

removing accumulated solids from their LAWMS without appropriate planning. There was the

potential for tremendous amounts of nutrients being washed into surface waters if indiscriminate

removal and land application of storage pond contents was to occur. A more environmentally

acceptable means of addressing the problem would be to provide planning assistance that would

reduce the amount of nutrients entering lakes and streams by providing guidance to individual

farmers that would improve nutrient utilization and overall manure management economics. In

order to provide effective assistance, the proposed project was structured to involve the producer,

local conservation districts and the EPD of ADEQ to develop plans that were economically

feasible, environmentally responsible, and within the limits of the state water permit issued for

the facility.

In an effort to address LAWMS issues observed in the Swine Project and the Solids Survey, the

“Land Application of Accumulated Solids From Liquid Waste Systems Demonstration Project”

(Land Application Project) was initiated. The project goal was to work with the swine industry

to address solids and nutrient accumulation problems at confined animal facilities having

LAWMS. The essence of the project involved working with farms that had on their own,

determined that there was a problem with accumulated solids within their LAWMS. Through

their own volition, participating farmers received assistance and training in proper waste system

operation as well as optimum management of nutrients derived from the system. Emphasis was

placed on accurately identifying waste characteristics and achieving the maximum fertilizer

benefit and the greatest protection of water quality. The EPD assisted farmers in 1) sampling

storage ponds, 2) proper land application of waste including information on nutrient benefits and

water quality protection, and 3) maintaining accurate and complete records of waste application

activities.

Participants in the project included:

Swine Corporations (Integrators)

Individual Swine Producers

Arkansas Pork Producers Association

University of Arkansas Department of Agronomy

Conservation Districts

Arkansas Soil & Water Conservation Commission

Results from the Swine Project and Solids Study were presented to farmers, to integrators and to

Conservation District Boards. ADEQ Regulation No. 5 requires all farmers having LAWMS to

attend an annual training meeting. These meetings provided a venue for direct interaction with

draft

18

every swine producer in the state. Prior to the official start of the Land Application Project,

information was presented at the meetings which emphasized the importance of removing solids

annually from LAWMS in order to reduce the amount of time spent managing manure and to

reduce the impact of swine facilities on water quality. Following the start of the project,

presentations at Regulation No. 5 meetings continued to focus on the problems associated with

accumulated manure solids and the Land Application Project was introduced. At the meetings

the following year, a case study was presented so that the farmers could actually see how the

clean-out plan development process took place. Copies of slides presented by project staff at

Regulation No. 5 meetings have been included as Appendix A of this report. Farmer

participation in the project was entirely voluntary and no costs were incurred by the farmer for

receiving planning assistance. Costs associated with sample collection and analysis, file review,

and plan development were covered entirely by the project budget.

The project team felt that, in order to improve farmer

participation, any planning assistance provided to

farmers in order to clean-out accumulated manure

solids should be coordinated through the local

Conservation District offices. Local Conservation

District offices had an established working

relationship with many farmers and provided an

avenue of trust and confidence that improved farmer

interest and participation in the program. All

Conservation Districts where swine facilities were

located were invited to participate in the project. It

was decided that personally meeting with the ten

districts having the greatest number of swine

facilities would be the best way to encourage their

voluntary participation. The districts having the

greatest number of swine facilities are shown on the

map in Figure 1 and are listed in Table 1, along with

the number of permitted farms within the district. A

formal presentation on the solids and nutrient

accumulation issue was made to each of the

Conservation District boards in order to solicit their

direct participation. Copies of the slides presented at

the board meetings are included in Appendix A.

Other conservation districts having swine facilities in their areas were sent a letter describing the

project and offering assistance to them should any producer from their district request a LAWMS

clean-out plan. Meeting with the conservation district boards required a significant investment

of time, but ultimately helped in generating interest from farmers and kept the planning process

local.

The project team also met with representatives of the major integrators and presented

background information developed from the Swine Project and Solids Survey. The goals of the

Land Application project were discussed and their cooperation in the project was solicited

allowing project staff access to contracted farms in order to evaluate the LAWMS of

Table 1. Numbers of Swine Facilities by

Conservation District (1999)

Rank Conservation

District

Number

of Farms

1 Mill Ck. (Howard) 50

2 Pope 43

3 Cossatot (Sevier) 42

4 Yell 28

5 Pike 27

6 Conway 23

7 Polk 21

8 Washington 21

9 Montgomery 20

10 Benton 18

11 Perry 12

12 Little River 12

13 Logan 12

14 Hempstead 12

15 Newton 11

16 Clark 9

17 Madison 8

18 Johnson 6

draft

19

participating facilities.

Pond Clean-Out and Land Application Planning

The system for developing pond clean-out plans was designed to proceed through the

conservation districts. The hope was that after completion of the project, water quality

technicians from the conservation districts would be able to provide the types of assistance that

EPD provided during the project. If an individual farmer suspected a solids accumulation

problem in his LAWMS, he would notify his local Water Quality Technician and request

assistance. Most producers were aware of a solids accumulation problem in their LAWMS,

because when they pumped water from their ponds, they could see “islands” of solids appear.

Some producers also experienced an inability to utilize their recycle flush pump due to

accumulated solids.

After a request for planning assistance was made, the Water Quality Technician then contacted

EPD staff who would schedule a trip to the farm to gather some of the necessary information

needed to develop a clean-out plan. In order to reduce the environmental effects and economic

burden of removing accumulated solids from LAWMS, the EPD staff developed farm specific

clean-out plans based on:

1. The mass of N contained within the ponds;

2. The mass of P contained within the ponds;

3. Permitted land application acreage available to the farmer;

4. The specific cover crop nutrient uptake requirement for maximum agronomic benefit;

5. Concentrations of STP on permitted land application sites;

6. Waste management equipment and resources available to the farmer;

The completed plan was discussed with the water quality technician and then delivered to the

farmer who was responsible for implementing the plan. The following section provides details

of the process for developing the LAWMS solids clean-out plans.

draft

21

IV. Solids Clean-Out Plan Development Strategy

Liquid Manure Characterization

The first step in preparing a plan to remove accumulated solids from a LAWMS was to estimate

the quantity and character of the manure being stored in the LAWMS. In order to accurately

characterize the manure in LAWMS, a sampling protocol was developed that would result in the

collection of samples that would be representative of the manure in the systems. The sampling

procedures developed were based on previous LAWMS sampling experience as part of the

Swine Project. Samples of the liquid manure in the LAWMS were collected using a modified

Coliwasa sampling device. This device is constructed of clear plastic graduated in 1 inch

increments and utilizes a rubber plunger and rod to open and close the sampler. It was found that

the composition of typical swine waste solids inhibited adequate sealing of the rubberized

plunger. The plunger was modified by increasing the bevel angle in order to overcome this

limitation. The modular design of the device allowed for adding the appropriate length of tubing

depending on pond depth. The sampling device could obtain column samples from holding

ponds up to a depth of 12 feet.

Figure 4. Collection of LAWMS Pond Samples

Composite samples of the holding ponds and settling basins (when present) were collected from

a boat, which was maneuvered by installing a guide rope across the pond along the sampling

paths (Figure 4). The column samples were taken at four equidistant locations along two passes

across the width of the holding pond. The discreet column samples were mixed thoroughly in a

bucket, and then a composite sample of the mixture was removed and placed in a sample bottle

for analyses (Figure 5). The method for collecting a composite sample from a settling basin was

the same as the holding pond, with the exception that four discreet samples were collected during

draft

22

a single pass across the length of the pond for compositing into one sample. At each of the

column sample locations, the total height of the collected column sample, the thickness of

stratified solids and liquid layers, and the total depth of liquid manure in the ponds were recorded

on a data collection sheet (Appendix B). The samples were delivered to the ADEQ laboratory in

Little Rock where they were then analyzed for TKN, NH3-N, NO3-N, TP, Ortho-P, TDS, TSS,

Cl, SO4, and TOC using EPA-approved methods.

Figure 5. LAWMS Pond Sample Collection Methodology

Some difficulties were encountered while using the sampling device. For example, accumulated

solids would not always freely move into the sampling device. These solids tended to block the

opening and prevent collection of representative samples of the entire depth of the pond. To

improve the quality of sample collected, the device was moved in an up and down manner to

facilitate more material entering the sampling device. The difference between the height of

sample collected and the total depth of the pond, was assumed to be made of Aunsampled@ solid

material. The mass of nutrients associated with the Aunsampled@ solids material was estimated

and then added to the mass of nutrients determined from the sampling event. In addition to

composite samples, discreet samples of the solids materials and the overlying grey water were

collected and analyzed from many of the facilities.

The volume of liquid manure was estimated based on measurements collected while in the field.

The holding pond/settling basin dimensions at the waterline and at the top of the pond levee and

the amount of available freeboard were determined by direct measurement. Using this

information, along with the depth of liquid manure in the pond, a determination of the volume of

draft

23

manure that was contained in the ponds could be made. Estimations of volume of manure in the

ponds could have been made by utilizing the dimensions of the pond in the construction plans for

the facility. However, as was frequently noted during the Solids Study, ponds were rarely built

as shown in construction drawings. Site limitations were often the cause of this discrepancy.

Visiting each of the farms and collecting the necessary data was crucial in order to develop site-

specific clean out plans. Included in Appendix B is a copy of the sample collection data sheet

and standardized pond sampling procedures used in this project.

Waste Management Plan Review

The second step in developing a LAWMS solids clean-out plan was to obtain and review the

farm specific Waste Management Plan (WMP), the ADEQ State Water Permit, and the most

recent Regulation No. 5 Annual Report submitted to ADEQ by the facility operator. From the

WMP, the amount of acreage available for land application, as well as the cover crop on the

pastures receiving liquid manure, could be ascertained. The ADEQ permit issued for the facility

was reviewed to determine the permitted acreage available for manure applications and the

maximum N based application rate. Soil test phosphorous (STP) concentrations for each field

that would potentially receive liquid manure were obtained from the Regulation No. 5 annual

report that each facility with a permitted LAWMS is required to submit to ADEQ.

Plan Development

With the information listed above, an initial solids clean-out plan was developed. The initial

plan provided the basic elements needed by the operator to accomplish the clean-out. A meeting

was then arranged with the farmer, the conservation district, and EPD project staff, so that the

information used to formulate the initial clean-out plan could be reviewed and finalized.

Attached as Appendix C is the LAWMS Solids Clean-Out Plan checklist and form developed

and used in the project. At the meeting, farm specific issues were discussed with the farmer so

that the final plan would be tailored to the needs and limitations of the particular facility. Issues

that had to be addressed in the finalized plan were numerous and varied with each facility.

However, issues common to all farms included: application rates; land requirements; equipment

requirements to accomplish the clean-out task; and the economics involved with removing large

volumes of accumulated manure solids. The farmer left the meeting with a clean-out plan

summary that included: the volume of manure; concentration of nutrients; total pounds of

nutrients contained in the LAWMS; the permitted acreage; STP values for each field; and

acreage requirements for the clean-out. Also, a copy of the composite manure sample analysis

was given to the farmer. Each farmer was made aware of the known waste management

companies servicing the swine industry in the state and was provided with a list of such vendors

(Appendix D).

The manure and nutrient application rate was one issue discussed with every farmer. As

indicated by the Swine Project and Solids Study, the concentration of nutrients in accumulated

manure solids is very high compared to concentrations indicated by the WMP. Typically, in

LAWMS with accumulated manure solids, the relative concentrations of N to P is approximately

a one-to-one ratio, compared to a ratio of 3 to 1 for manure as excreted by gestating sows 7.

Current planning practices in Arkansas develop WMPs using N as the basis for land application

draft

24

rates since N is the limiting nutrient to forage growth. If the accumulated manure were to be

land applied at the N based application rate, the amount of P applied would greatly exceed the

cover crop=s ability to uptake P. This is cause for concern since phosphorus is a potential

pollutant in surface water. Reducing phosphorus loss from manure fertilized fields through

storm water runoff had to be addressed when developing the clean-out plans. As a matter of

project policy, EPD project staff recommended that farmers apply their manure at 2 the N based

application rate in order to reduce the over-application of phosphorus. Application of manure at

half the N rate not only reduced the amount of P that would potentially run-off during rainfall

events, but it also reduced the rate at which pastures receiving manure accumulate STP. If at

some future date WMPs for confined animal operations were to be based upon STP and an

application index, many fields might be unusable for manure application as a result of current

poorly planned nutrient applications. Farmers were also encouraged to land apply the manure

during the months of greatest nutrient demand by the growing cover crops.

Another method of reducing P loss was to land apply manure to fields with lower STP values.

While working on the Swine Project, high STP values were frequently noted on the fields nearest

to the barn complex and waste system. Similar conditions were observed during the Land

Application Project (Figure 6).

Therefore, as a matter of practice,

discussions with each farmer about

nutrient management included

ways of controlling and reducing

STP levels. Farmers were

encouraged to avoid applications of

accumulated manure solids with

high P concentrations to fields with

greater than 300 pounds per acre

STP. In addition, it was

recommended that fields adjacent

to the LAWMS could be held in

reserve in order to keep them

available for emergency pond level

control throughout the remainder of

the year. Management practices that could be used to control or reduce STP in storm water

runoff were presented to all

participating farmers. Mining of P

from fields having high STP levels

by intensively managing fields for

hay production and the use of pasture renovation in conjunction with manure applications was

encouraged. Effective mining of P requires that forage be removed from the field, as opposed to

allowing cattle to graze on the grass and, in effect, recycling the nutrients back to the pasture.

Utilization of pasture renovation, in theory, can increase the distribution of P through a greater

soil depth as well as reduce the amount of storm water runoff by increasing the porosity of

pasture soils. The effectiveness of pasture renovation in Arkansas is being investigated by the

EPD in the “Pasture Renovation To Reduce Nitrogen and Phosphorous Run Off From Fields

Fertilized With Animal Manure Demonstration Project” currently underway8. In addition to the

Figure 6. High STP Adjacent to Facility

draft

25

practices described above, the importance of monitoring STP levels on each field through regular

testing and utilizing good sampling methodology was stressed.

Since, historically, WMP designs set the manure application rates based upon the N content of

the manure expected from the number of animals in confinement, many farms acquired the

minimum amount of permitted land required to assimilate the predicted annual nutrient load.

Therefore, when LAWMS accumulate manure solids and associated nutrients, there is frequently

a shortage of land application acreage to accommodate a system clean out, particularly, if the

manure is applied at one-half the nitrogen rate. During the Land Application Project planning

process, solutions to this commonly observed problem included adding land application acreage

to the permit or reducing the rate of application and accomplishing the clean out over two or

three growing seasons. If producers elected to add additional land to their permits, they were

advised to add as much as possible, since the associated cost of modifying a permit is not

dependent on the acreage being added. Producers were encouraged to actively develop a market

for the fertilizer by adding as much of their neighbors land to the permit as possible within a

reasonable haul distance from the facility. Surplus manure could then be sold, partially

offsetting management costs.

Knowing the manure volume, associated nutrient content and the acreage required for the clean

out, the farmer was better able to determine his financial ability to address the problem. Few of

the farmers who requested planning assistance through this project had the necessary equipment

to manage high solids content sludge or the time required to accomplish the clean-out task on

their own. Clean-out cost estimates for participating farms, based upon commercial waste

management services pricing of approximately 1 cent per gallon, ranged from $3000.00 to over

$30,000.00. Few Arkansas swine farmers have the financial means for a one-time clean out of

years of accumulated solids. This financial impediment, in addition to insufficient permitted

land application acreage, resulted in many producers electing to have their plans developed so

that the problem could be addressed incrementally over two or more growing seasons.

After the plan was finalized, a clean-out plan summary was completed. The summary was

intended to be a document that could be given to a manure management contractor or used by the

farmer to follow during clean-out activities. It included the pond volume and nutrient content

estimates as well as nutrient application rates for each field. Implementation of the final plan

within the target time frame was up to the farmer. Follow up visits by water quality technicians

or project staff were made to many cooperating farms in order to monitor progress. A copy of

the Clean-Out Plan form is included in Appendix E of this report.

After completion of the project, a 3 ring binder containing all of the necessary information to

develop a comprehensive LAWMS solids clean-out plan was presented to participating

Conservation Districts, ASWCC, Arkansas Cooperative Extension Service, the Arkansas Pork

Producers, and other entities. This binder and contents are referred to as the “Swine Manure

Solids Clean-out Planning Resource Notebook.” The notebook included most of the information

contained in the appendix of this report, as well as tools to make the planning process quicker.

Specifically, a spreadsheet program was provided that allows planners to quickly calculate

manure volume and nutrient masses found in a LAWMS given that the system has been sampled

previously. A copy of the notebook can be obtained electronically from the ADEQ,

draft

26

Environmental Preservation Division.

draft

27

V. Project Results

Eighteen facility operators

requested LAWMS clean-out

planning assistance through the

Land Application Project. The

location of the facilities that

participated in the program are

shown in Figure 7. Although the

project staff met with, presented

and discussed the issues of

accumulated swine manure solids

with 10 conservation districts,

only 4 of those districts had farms

that participated in the project.

Two districts that had

participating facilities did not

receive a formal visit. Table 2

shows the 6 participating

conservation districts and the

number of clean-out plans

developed and executed. The top

swine producing district in the

state (Howard County, Table 1)

did not have any farms participate in the program. Participation rates were dependent on

producers’ interest in obtaining assistance and whether or not the conservation district was

actively promoting the assistance being provided through the project. In Sevier County, Cossatot

Conservation District, participation rates were the highest due to the interest and promotion of

the project provided by the water quality technician.

Table 2. Plan Development and Clean-outs by County

County Plans

Developed

Clean-Outs

Completed Conway 2 2

Monroe 1 0

Newton 2 2

Pope 2 2

Searcy 1 1

Sevier 9** 0** **3 Facilities had lagoon systems that did not require a clean-

out

Table 3 provides an overview of the LAWMS characteristics, the concentration and mass of

nutrients and the amount of accumulated solids at facilities that received planning assistance.

Participating facilities were swine operations with the exception of one dairy facility. Although

the project was originally oriented towards the swine industry, the principle investigator and

project staff agreed that any facility having a LAWMS could receive clean-out planning

assistance through this project. Reviewing the characteristics of the facilities participating in the

project, the differences of the types of LAWMS can be identified. None of the facilities that

Figure 7. Locations of Participating Facilities

draft

28

participated in the project had LAWMS that were identical. Some facilities were similar in one

aspect, pond size for example, but varied in the available acreage or concentration of nutrients in

the system. The volume of liquid manure that needed to be addressed during the course of the

project ranged from approximately 175,000 gallons to near 3.2 million gallons. Concentrations

of nitrogen and phosphorus in the systems ranged from 6 and 7 lb/1000 gal to 65 lb/1000 gal

respectively. The amount of pond volume occupied by accumulated manure solids ranged from

4 to 100 percent. Differences in these and other variables identified while providing planning

assistance to farmers participating in the project emphasized the importance of farm specific

planning when developing plans for a LAWMS solids clean-out.

Every facility operator that requested clean-out planning assistance through the Land Application

Project received a completed plan. A copy of an example completed plan is included in

Appendix F. Of the 18 facilities that requested assistance for developing a clean-out plan, only 7

facilities were able to execute the plans by the end of the allotted project time-frame. However,

three of the 11 remaining facilities that had not executed a LAWMS clean-out were Lagoon

designs that were in a condition that did not require immediate removal of the solids. The factors

affecting the ability of a producer to execute a clean-out plan include: pond size; pond access;

insufficient permitted application acreage; high STP on some fields; travel distance from the

waste system to suitable permitted application sites; and cost associated with hiring a contractor.

All of these factors are interrelated, for example, the size of the pond increases the amount of

nutrients that would be land applied, which increases the acreage requirements. Also, the larger

the storage pond, the greater the cost for cleaning out the LAWMS will be. Greater amounts of

nutrients also increased the travel distance required to reach enough land to assimilate the

nutrients which in turn increases cost. These issues were common to all of the facilities

requiring a solids clean-out, and for the systems that were not able to complete the clean-out by

the end of the project, a combination of these factors was frequently to blame.

The issue of available acreage and distance to land was one that frequently resulted in delays in

executing a LAWMS clean-out. Table 4 indicates the acreage requirements for land applying the

accumulated manure and nutrients from the facilities participating in the project. In Table 4, the

number of acres indicated on the permit, the number of acres with STP over 300 lb/ac, acreage

available to receive land applied manure after excluding high STP acreage, the number of acres

needed to land apply at the full nitrogen application rate, and the acreage required to land apply

at one-half the nitrogen application rate are listed for each facility.

Review of the data in Table 4 indicates that 7 of the 18 facilities did not have sufficient acreage

to have the manure and nutrients applied at the full nitrogen application rate. As the purpose of

the planning process was to reduce the over application of phosphorus, plans were developed

such that the manure would be applied at one-half the nitrogen application rate. Application of

accumulated manure solids at the permitted nitrogen application rate would have resulted in poor

utilization of nitrogen fertilizer value and over application of phosphorus. Additionally, while

the State issued permit may allow up to 300 lb N/ac/yr in some permits, the intent of the

permitted application rate is to have multiple applications of manure throughout the growing

season that when totaled are equivalent to 300 lb N/ac/yr. All of the facilities participating in the

project agreed that the best use of the accumulated manure was to land apply at one-half the N

rate. Based on the one-half

draft

29

Table 3. LAWMS Characteristics of Project Facilities

Farm

Number County

Type of

Operation

Number of

Animals LAWMS

Manure

Volume (gal)

N and P Conc

(lb/1000 gal) Mass N and P (lbs)

% Pond

Volume

69 Sevier Finishing 2400 HP

SB

568,400

210,700

50

38

38

18

28,500

7,960

21,500

3,800 40

38 Sevier Farrowing 300 sow HP 480,000 24 30 12,000 14,000 45

72 Sevier Finishing 2500 Lagoon 1,401,000 55 65 77,150 90,900 55

34 Sevier Farrowing 300 sow HP

SB

920,000

57,000

38

28

30

20

35,000

1,600

27,600

1,100 42

88 Sevier Farrowing 300 sow Lagoon 1,454,000 13 15 19,000 22,000 5



25 Sevier Finishing 2500 Lagoon 3,158,000 34 26 107,000 82,000 40

61 Sevier Farrowing 300 sow HP 577,000 29 34 16,700 19,700 58

15 Conway Finishing 4000 HP

SB

1,000,000

215,000

50

32

45

18

50,000

6,900

45,000

3,900 40

86 Conway Finishing 4080 HP

SB

1,844,000

376,254

45

23

46

28

83,000

8,700

84,000

10,600 36

51 Monroe Finishing 400 HP 1,381,000 47 36 65,000 50,000 100

30 Pope Farrowing 300 sow HP

SB

280,000

35,000

65

29

65

22

18,000

1,000

18,000

800 50

163 Pope Finishing 2400 Lagoon

SB

549,000

n/a

40

n/a

33

n/a

22,000

n/a

18,000

n/a

29

n/a

16 Newton Farrowing 300 sow HP

SB

150,000

22,000

28

37

26

31

4,300

810

4,000

680

38

n/a

19 Newton Farrowing 300 sow HP

SB

153,000

170,000

22

25

23

24

3,400

4,300

3,500

4,100

22

9

25 Searcy Farrowing 340 sow HP

SB

220,000

40,000

48

28

50

25

10,500

1,100

10,900

1,000

40

100

37 Searcy Dairy 100 cow HP 220,000 14 5 3,100 1,100 47

draft

30

application N rate, all but two facilities that had a clean-out plan developed needed additional

acreage in order to complete the clean-out process in one year. The time requirements and

difficulties in obtaining additional land precluded many operators from conducting a clean-out of

their LAWMS immediately upon receipt of the clean-out plans. This was the case for a number

of the facilities in Sevier County where land, that is available to be added to a permit, is scarce

due to the number of confined animal operations in the area (both swine and poultry).

Table 4. Available Acreage and Land Application Acreage Requirements for Participating Project Facilities

Farm

Number County

Permitted

Acres

Acres with

>300 lb/ac

STP

Available

Acres

Acres Required

for Full Nitrogen

Application Rate

Acres Required

for 2 N

Application Rate

69 Sevier 545* 5 460 151 302

38 Sevier 8 40 58 50 100

72 Sevier 187 67 120 240 480

34 Sevier 261 0 261 152 304

88 Sevier 86 2 84 65 130

95 Sevier 37 0 37 36 72

98 Sevier 69 0 69 190 380

25 Sevier 214 80 134 353 706

61 Sevier 57 37 20 54 108

15 Conway 708** 0 476 381 762

86 Conway 316 0 316 553 1106

51 Monroe 480 0 480 648 1296

30 Pope 120 42 78 65 130

163 Pope 113 0 113 72 144

16 Newton 111 18 93 23 46

19 Newton 69 17 52 43 86

25 Searcy 278 9 269 70 140

37 Searcy 45 29 16 21 42

* All permitted land application acreage is owned by other landowners. Manure application activities are subject to

individual owner land management requirements.

* *Approximately 232 acres are located more than 10 miles from the barn complex.

A summary of the clean-out activity status for each of the 18 facilities participating in the project

can be found in Table 5.

draft

31

Table 5. Summary of Land Application Planning and Clean-Out Status

Farm

Number County Clean-Out Status Summary of Clean-Out Activity

69 Sevier Partial Clean-Out

Solids were removed from the settling basin and approximately half of the accumulated

solids were removed from the holding pond. Both of the ponds are difficult to access

with waste management equipment due to steep inside and outside levy slopes. None of

the permitted application acreage is owned by the farmer, therefore all land application

activities are subject to the management decisions of the individual land owner.

38 Sevier Partial Clean-Out Approximately half of the accumulated solids were removed from the holding pond.


The farmer added 100 acres of land application acreage to the permit. The facility has a

large holding pond with narrow levee crest and steep inside and outside slopes which

severely limits equipment access. The land application sites in closest proximity to the

waste system had high STP values.


The clean-out was completed in July of 2002. A contractor was hired to accomplish the

task. The farmer reported that 700,000 gallons of solids were removed from the ponds

and land applied according to the clean-out plan. Some solids were left due to an

insufficient volume of water to mix with the holding pond contents for pumping and

removal.

88 Sevier Clean-Out Not

Required

The waste storage structure consist of an anaerobic lagoon. The structure was in good

shape without a large accumulation of solids. An unfavorable N:P ratio of 1:1.2 was

noted in the solids contained within the lagoon.


Required


shape without a large accumulation of solids. However, an unfavorable N:P ratio of

1:1.2 was noted in the solids contained within the lagoon.


Required


shape without a large accumulation of solids. However, an unfavorable N:P ratio of 1:2

was noted in the solids contained within the lagoon.


The structure had a considerable solids content and the surface area (1.78 acres) and

waste volume (3.158 million gallons) made for a formidable clean-out task. Standard

agitation equipment is ineffective due to pond size. The farmer irrigated gray water and

hired a contractor to remove $10,000 worth of solid.

draft

32

Farm


61 Sevier Complete

The farmer added 60 acres to the permit. Considerable solids accumulation was found in

the pond in which an N:P ratio of 1:1.1 was noted. The clean-out was begun in the

summer of 2001 and completed in the summer of 2002.

86 Conway Complete

The facility has a large holding pond with just under an acre (.92 acre) of surface area.

Equipment access to half of the holding pond was difficult due to narrow levee crest and

steep side slopes.

15 Conway Complete

The farmer opted for an incremental clean-out in order to spread out the expense. The

holding pond was built by constructing an earthen dam across a draw. It has a relatively

large surface area (.75 acre) with steep inside slopes and a narrow dam crest which

effectively restricts equipment access to most of the structure. The farmer focused on

removing the solids in the settling basins and the solids effecting flush pump operation in

the holding pond. Although 708 acres are permitted, 350 acres are more than 10 miles

from the barn complex effectively rendering this land unusable due to excessive hauling

expense . Of the remaining land, 67 acres had high STP levels. A considerable quantity

of solids remain in the holding pond.

51 Monroe Incomplete

The holding pond is relatively large with approximately an acre of surface area.

Equipment access to half of the structure is limited due to the close proximity of the

pond to the barns and a drainage ditch. The farmer did not clean-out due to family

medical problems, low commodity prices and high clean-out cost.

130 Pope Complete

The ponds were cleaned out in July of 2000. Equipment access to the settling basin and

two sides of the holding pond are difficult due to proximity to the barns. In addition, a

narrow levy crest with steep inside and outside slopes further limits access to the ponds

with waste management equipment. The farmer added 42 acres of land to his permit and

avoided application to approximately 66 acres due to high STP levels. The clean-out

was accomplished in split applications over the course of a growing season to intensively

managed bermuda grass hay.

163 Pope Complete

The ponds were observed to be empty in October 2001. Although the holding pond does

not have a large surface area, it is deep with narrow levy crest and steep inside and

outside slopes making equipment access difficult. The farmer added 31 acres to the

permit. The clean-out was accomplished in a late summer and spring application to 113

acres.

draft

33

Farm


16 Newton Complete

The ponds were observed to be empty in August 2000. Access to the holding pond was

very difficult due to a narrow levee crest and steep side slopes. The farmer added 60

acres to his permit. The clean-out was accomplished in a mid growing season

application to approximately 42 acres. Due to high STP levels, manure application to 18

acres of permitted land was avoided.

19 Newton Complete

The ponds were observed to be empty in May of 2000. The ponds did not have a large

surface area however equipment access was difficult due to steep uphill slopes and steep

levy side slopes with a narrow crest. Manure application to 17 acres was avoided due to

high STP levels. Waste from the clean-out was applied to 35 acres, 24 of which is

intensively managed for bermuda grass hay production.

25 Searcy Complete

The ponds were observed to be empty in August of 1999. Equipment access to 3 sides of

the holding pond is restricted by a pasture fence. Manure application to 9 acres was

avoided due to high STP values.

37 Searcy Complete

The holding pond at the dairy farm was observed to be empty in August 1999.

Equipment access was hindered by narrow levy crest with steep inside and outside

slopes.

draft

34

Returning to Facilities After Clean-Out

One facility that received

clean-out planning was

revisited two consecutive

years following the initial

clean-out of accumulated

solids. The difference in the

mass of nutrients in the

holding pond of that facility

one year subsequent to the

initial pond clean-out was

dramatic. Figure 8 indicates

that the concentrations of

nitrogen and phosphorus are

nearly three times less in a

pond receiving annual clean-

outs when compared to the

concentrations of nutrients in

the pond before the initial

clean-out was conducted.

Proper maintenance and annual clean-outs of LAWMS as prescribed by facility permits results in

a liquid manure with nutrients that are less concentrated and less likely to result in loss of

phosphorus to surface waters. Slight year to year variations of average nutrient concentrations in

annually maintained LAWMS should be expected due to variations in precipitation that may

dilute the liquid manure.

Analysis of manure samples

Figure 8. Nutrient Concentrations in Holding Ponds Prior to and

Following Annual Manure Solids Removal

Figure 9. Concentration of Nutrients Found in Various Phases of

LAWMS Manure Storage

draft

35

Over the course of the Land

Application Project, numerous

manure samples were collected

and analyzed in order to assist

in the development of

LAWMS clean-out plans. The

raw analysis data for samples

collected during the course of

the project can be found in

Appendix G. Figure 9 shows

the average concentrations of

various components of manure

found in LAWMS. The

components shown in the

graph include: the Asolids@

found at the bottom of the

pond, the Acomposite@ or the

average of the holding pond if it

were completely mixed, the Agrey@ water at the top layer of the pond, and the composite of the

Asettling basin@ if the settling basin were completely mixed. The information in Figure 9

depicts the differences in nutrient concentrations for the various stratified components of a

LAWMS. As expected, nutrient concentrations in the solid materials was much higher than the

concentrations found in grey water and, as solids accumulate in LAWMS, the mass of nutrients

also increased. The average concentration of nitrogen and phosphorus for composite samples

collected from the12 facilities that utilized a holding pond for manure storage was 30 and 28

lb/1000 gal respectively. Figure 10 shows the concentrations of other analytes for holding pond

composite samples that were collected and analyzed. Samples of manure solids were collected

from the bottom of the ponds of twelve facilities.

Both nitrogen and phosphorus concentrations averaged 81 lb/1000 gal. Figure 11 displays the

concentrations of other analytes in the high solids content layer of swine liquid manure holding

ponds. Comparing concentrations of sulfate from the composite average and solids average

shows an increase of nearly 4 times, from 4 to 15 lb/1000 gal. Higher concentrations of sulfates

in manure solids indicates that as

solids accumulate over time, the

potential for air quality

degradation both in-situ and

during land application may

increase. Removal of manure

solids on a regular basis would

reduce the potential for air quality

degradation at swine facilities.

Grey water samples were not

collected as frequently as samples

of other components. Only five

grey water samples were collected

Figure 10. Concentration of Analytes in Composite Samples

Collected From Holding Ponds

Figure 11. Concentration of Analytes in Accumulated Manure

Solids Samples Collected From Holding Ponds

draft

36

over the life of the project. This was primarily due to the fact that grey water concentrations

were generally not required to develop an effective clean-out plan. To reduce time and expense

of analysis, grey water samples were not collected frequently. For the five samples that were

collected, the average concentration of nitrogen and phosphorus for the grey water samples was

5 and 1 lb/1000 gal respectively. These numbers are similar in scale to the average

concentrations submitted by producers to the state in the Regulation No. 5 annual reporting

process. The similarity between the grey water analysis and the concentrations reported in

Regulation No. 5 reports indicates that many producers are not effectively mixing the contents of

the LAWMS prior to the land application of the liquid manure.

draft

37

VI. Clean-Out Case Study

In order to insure that all of the issues and concerns associated with a waste system clean-out

plan development and implementation were addressed, a farm was selected as a test case. The

goal of the test case was to insure that waste volume and nutrient content predictions were

accurate prior to beginning work with other farms. Another important objective was to develop a

standard process for addressing problems common to many farms in the swine producing areas

of the state. The farm selected for the test case was also used in the aluminum chloride

demonstration component of the project which will be discussed later in this report.

The clean out test case farm was a typical 10 year old facility utilizing total confinement of

animals and built during a period of rapid swine industry growth in Arkansas in the late 1980's

and early 1990's. The farm is located in the Ozark Mountains of the north-central part of the

state. It is a contract growing operation and was originally built as a 240 sow, farrowing-nursery

operation in which pigs produced on the farm were raised to 40 pounds at which time they were

shipped to a finishing operation. During the clean out planning process the farm was being

converted to a 360 sow farrow-to-wean operation in which the pigs are shipped off site to a

nursery operation when weaned at 10 pounds. Both operations utilize total confinement of sows

within the barns.

The waste system consisted of a settling basin and holding pond with a recycle flush system.

Water pumped from the holding pond is used to flush the length of each barn where it collects

animal waste and transports it to the settling basin. Solids remain in the settling basin while gray

water overflows to the holding pond. Surplus liquid and animal waste is periodically land

applied with a gasoline powered pump and several hundred feet of 3 inch plastic line through an

irrigation gun. In addition, a tractor pulled 1000 gallon capacity honey wagon was available for

land applying manure to the more remote fields. The farm had approximately 84 acres

permitted for land application, of which, 19 acres nearest to the barn complex had STP levels

greater than 300 pounds per acre (Figure 6). The farmer was advised to avoid application to this

area. Additionally, 20 acres of permitted land was roughly 20 miles from the barn complex, too

far to be feasible for use as land application acreage. Of the permitted land, 45 acres was

suitable for land application.

As with most farms, permit required freeboard levels were maintained by pumping the ponds

from the top. The farmer did not own agitation equipment and did not mechanically mix the

pond contents during routine land application activities, consequently a considerable volume of

solids had accumulated. Another factor contributing to solids accumulation at this farm was the

recycle flush pump intake configuration. Rather than floating the intake so that water could be

pumped over a wide range of pond levels, it was fixed to a post. This required the pond to be

maintained at a minimum level in order to operate the recycle flush system. This is not an

uncommon flush pump configuration at farms in Arkansas and contributes significantly to the

solids accumulation phenomenon. If the farmer drops the pond level below the recycle flush

pump intake, the barns cannot be properly cleaned until the liquid level recovers. During the

time interval in which the barns are not flushed, manure must be scraped and removed from the

barns by hand or allowed to accumulate which creates sanitation concerns.

draft

38

Pond measurements and samples of the waste system were collected on July 15, 1999 utilizing

the standard sampling methodology developed for the project and included in Appendix B of this

report. From this information the manure volume was estimated to be 225,000 gallons with the

total mass of nutrients estimated to be 10,500 pounds and 10,000 pounds for N and P

respectively. The estimated waste system volume turned out to be 3.6 percent higher than the

actual volume of waste removed during clean-out operations. This is considered to be a very

good pond volume estimate. Based upon the initial waste system characterization it was evident

that there was insufficient permitted land application acreage available for the clean out,

particularly if manure was to be applied at a reduced N based rate and the 19 acres exceeding

300 pounds per acre STP were to be avoided. Fortunately, the farm is located within a

geographical area of low confined animal operation density and the cooperating farmer had no

trouble in locating suitable additional acreage near the farm. Project staff assisted the farmer in

requesting one time land application authorization from the State Permits Branch of ADEQ for a

12 acre and 220 acre tracts of land. The request was approved conditionally, based upon the

tracts being added to the list of land application sites by a formal permit modification within a

specified time frame.

The waste system clean out took place over four days in early August of 1999. A waste

management contractor was hired and project personnel were on site to observe and collect waste

samples. Activities related to the Aluminum Chloride Demonstration were conducted

concurrently and are discussed later in this report.

Considerable differences in predicted and measured nutrient concentrations in LAWMS were

noted by project staff in the Swine Project as well as the Solids Survey. Based upon a

Regulation No. 5 requirement, each

operator of a permitted LAWMS

must collect a manure sample

annually, which the Cooperative

Extension Service laboratory

analyzes for nutrient

concentrations, and submit a copy

of the analysis to the State Permits

Branch. An evaluation of two years

of data for all facilities in the state

by project staff indicated nutrient

concentrations for virtually all

samples submitted were more

typical of the surficial gray water

layer of a non-maintained stratified

pond. Nutrient values for the

typical waste analysis submitted

were also noted to be considerably

lower than predicted values in individual facility Waste Management Plans (WMP).

Furthermore, both the waste analysis reports and the WMP predicted nutrient concentrations

were considerably lower than values obtained from composite samples collected using

Figure 12. Comparison of Nutrient Concentrations From Various

Clean-Out Planning Data Sources

draft

39

methodology developed in the Swine Project. Figure 12 clearly depicts the wide-ranging

differences between the concentrations of total N and P for which a clean-out plan for the facility

could be based. If the clean-out plan were to be based upon nutrient values derived from the

Regulation No. 5 waste analysis, the plan would underestimate the nutrient mass in the ponds,

consequently nutrients would have been over applied by approximately 6.5 times. For the

particular facility in the example, that would have resulted in an application rate of 900 lb

N/acre. Over application of manure by this magnitude could have serious deleterious effects on

water quality as well as adverse health effects on grazing ruminants from nitrogen toxicity. Even

utilizing the WMP derived nutrient values would have resulted in an over application by 2.8 and

3.3 times for N and P respectively. That is not to say the WMP was developed incorrectly. If

the farmer had removed the solids annually the concentration of nutrients in the pond would

most likely mimic what is found in the WMP. In fact, review of Figure 8 shows that for the

facility that was revisited after successive clean-outs, nutrient concentrations in the holding pond

were found to be similar to the values predicted in the WMP for the facility of interest in the case

study. Although the facilities are very similar, slight variations in average nutrient concentration

from year to year should be expected due to differences in annual precipitation.

Figure 13. Houle "AgiSprayer" Equipment Used For Agitation

During Pond Clean-Out Process

draft

40

The manure that was land

applied during the clean-out

process was sampled to

determine if the composite

samples collected using the

described methodology were

accurate predictors of the

concentrations of nutrients that

would eventually be land

applied. This was done by

collecting samples from the 3150

gallon tank spreader that was

used for land application of the

pond contents. The pond was

thoroughly agitated for

approximately 1 hour prior to

beginning the land application

process. Agitation was

accomplished using a PTO and

hydraulically driven Houle AAgiSprayer@ shown in Figure 13. Samples were collected from

every 7th

tank load for the first 22 loads and then every 5th

load for the remaining land applied

tank loads. The samples that were collected were sent to the ADEQ laboratory for analysis. The

results of each of the analyses were averaged to arrive at a value for the average concentration

nutrients that were actually land applied by tank spreader. Figure 14 shows a comparison of the

concentration of nutrients predicted by the composite sample collection methodology to the

concentration of nutrients in the land applied liquid manure. Utilizing the composite sample

analysis resulted in an under-estimation of 8% for total nitrogen and an 16% over-estimation of

total phosphorus when compared to the actual concentration of nutrients applied during the

clean-out process. Although there is some difference in the predicted and measured

concentrations, composite sampling resulted in a far superior method of prediction when

compared to annually reported or WMP concentrations. Additionally, in this particular case, the

collection of the composite sample resulted in a conservative nutrient estimate that would further

reduce phosphorus runoff in storm water and accumulation in receiving soils.

Figure 14. Comparison of Composite Sample Results to Samples

Collected From Land Application Equipment

draft

41

All the correct and proper

planning that goes into a

LAWMS clean-out plan can

easily be undone during the

actual land application process.

In the case study, project

planners developed a plan that

the cooperating producer had

reviewed and agreed to

implement. The plan called for

application of the manure to

pastures with low STP

concentrations (less than 300 lb

P/ac) and at one-half the

permitted nitrogen application

rate. The planned application

rate was to be 75 lb N/ac. The producer went through the extra effort of obtaining additional

land for the clean-out to be executed properly. The project staff had experience with the

contractor hired to perform the pond clean-out and using a map of the facility, clearly explained

to the contractor where the manure was to be land applied and what the application rate should

be. The contractor did as was instructed and did not apply to pastures that had high STP values.

However, even with what were

supposedly clear instructions on

proper application rates, many

pastures ended up receiving the

full application rate. The mistake

was discovered during the clean-

out process and quickly rectified.

However, this occurrence shows

the importance of a responsible

person observing and paying

attention to the contractor

providing the clean-out services to

insure that the clean-out is

performed in a way that is

consistent with the developed

clean-out plan.

Tank Spreader Sampling

As described in the previous section, the tank spreader used for land application of manure being

cleaned out was sampled every 7th

tank load for the first 22 loads and then every 5th

load for the

remaining land applied tank loads. Samples were also collected and analyzed every 7 loads from

the tank spreader used during a clean-out procedure at another participating facility. The

observed changes in nutrient concentrations as a pond clean-out progresses are shown in Figures

15 and 16. Nitrogen and phosphorus concentrations increased by 54 and 42 percent respectively

Figure 15. Nutrient Concentration Change in Samples collected From

Tank Spreader During Clean-Out at Case-Study Facility

draft

42

from the first collected sample to the final sample collected at the case-study facility. At the

other facility where tank sampling was conducted, the concentration of nitrogen and phosphorus

increased 63% and 45% from the first to the last sample that was collected from the tank

spreader. The observed changes in concentrations during the clean-out process will be the most

dramatic as agitation efficiency decreases. Less effective agitation will result in a mixture of

liquid manure that is not homogeneous and would result in changes in nutrient concentrations as

the clean-out progresses. This information emphasizes the point that effective agitation is

important in achieving a uniform mixture for land application and that during the planning of a

pond clean-out, considerations could be made to incorporate the changing concentrations over

time and to adjust application rates accordingly.

Figure 16 Nutrient Concentration Change in Samples Collected From

Tank Spreader During Clean-Out at a Second Participating Facility

draft

43

VII. Aluminum Chloride Demonstration and Economic Alternatives

An important component of this project involved working with the University of Arkansas,

Fayetteville Campus, the APPA and a cooperating farmer to demonstrate the effectiveness of

treating swine manure slurry with aluminum chloride prior to land application. This project was

initiated in an effort to reduce soluble P concentrations in storm water runoff following land

application of liquid swine manure. Aluminum chloride has been used in municipal and

industrial waste water treatment applications for decades and could prove to be a valuable tool in

reducing agriculture related non-point source pollution, particularly in watersheds with a high

swine farm density.

The evaluation of the manure treatment methods was conducted at the same participating facility

that was used as a test planning case in Section VI. A description of the facility can be found in

Section VI.

Figure 177. Addition of Aluminum Chloride to Holding Pond

The goal of this portion of the project was to treat the contents of a holding pond with aluminum

chloride in an effort immobilize soluble reactive phosphorus (SRP) prior to land application.

The manure in the holding pond was to be treated in-situ because the condition of the holding

pond, having accumulated manure solids, represented a common scenario at Arkansas swine

production facilities. In order to quantify and characterize the pond contents for the aluminum

chloride treatment as well as to develop a clean-out and land application plan, the ponds were

sampled utilizing the pond sampling methodology described in Section IV. However, in addition

draft

44

to composite samples of both ponds, discreet samples were collected at one foot intervals. From

the analytical results, the mass of P and N were estimated and the nutrient concentration of each

distinct strata within the structures was determined.

Approximately two weeks after the initial sampling event, project workers arranged for a

contractor to be on site to mechanically mix the holding pond so that additional samples could be

collected. This was done in order to allow the U of A to conduct laboratory bench test to

determine the quantity of aluminum chloride required to effectively treat the pond contents. In

addition, the mixing capability of the agitation equipment was evaluated at this time. The pond

was mixed with a Houle Agisprayer powered by a 100 horse power tractor. The Agisprayer is

equipped with a power take off (PTO) driven propeller agitator with a sludge pump and spraying

capability for directing a high pressure stream of liquid waste at compacted solids. After

mechanically mixing the pond contents for approximately four hours, two 10 liter composite

samples were collected and delivered to the U of A Department of Agronomy laboratory.

Results of the bench tests indicated that the quantity of aluminum chloride required to treat the

entire volume of waste in the holding pond was beyond what could practically be transported to

the site. Therefore, it was decided that approximately half of the pond contents would be

removed and land applied prior to adding aluminum chloride. The pond was mechanically

mixed and land application operations began in early August 1999. Approximately half the pond

contents were removed and land applied with a 3150 gallon tank spreader.

Prior to treating the remaining liquid manure in the pond with the aluminum chloride, a 400

gallon sample of uniformly mixed manure (untreated) was collected to be used by the U of A on

rainfall simulation test plots fertilized with untreated manure. Land application activities ceased

while the aluminum chloride was blended into the pond. A two inch PVC pipe was extended

from near the propellor of the AgiSprayer to the trailer holding four 275 gallon containers of

treatment chemical (Figure 17). As the pond contents were mechanically mixed the aluminum

chloride was added, by gravity flow, and blended into the pond as thoroughly as possible. One-

half of the total volume of aluminum chloride was added to the pond and then the equipment was

moved to the other end of the pond where the remaining aluminum chloride was added. This

was done to improve the distribution of aluminum chloride throughout the liquid manure.

Following uniform mixing, land application activities were resumed and a 15 gallon sample of

the treated waste was collected after each 5 tank spreader loads (17,500 gallon intervals) and

composited into 400 gallon tanks. This treated manure was utilized on the U of A rainfall

simulation test plots fertilized with treated manure.

The report produced by the University of Arkansas Department of Agronomy on demonstrating

the effectiveness of adding aluminum chloride to liquid swine manure in order to reduce SRP

runoff has been inserted into the text of this report in it=s entirety.

University of Arkansas Report on Alum Addition

Introduction The swine industry today contends with two significant issues, odor and phosphorus (P)

runoff from agricultural land fertilized with swine manure. Even though the number of poultry

draft

45

producers exceed that of swine producers, more complaints associated with odor are issued to

swine producers. Fields receiving animal manure applications are under great scrutiny due to

alleged P inputs into water systems. Hence, alternative management practices may be necessary

to reduce potential odor and P runoff problems.

Ammonia (NH3) is one of the primary components odor from swine facilities. Conchal

atrophy (Drummond et al., 1981) and atrophic rhinitis (Robertson et al., 1990) are respiratory

ailments associated with high NH3 levels. Ammonia not only impacts swine, but also people

working in swine rearing facilities houses. Donham (1996) reported that 50% of the people

working in poultry houses had serious upper respiratory problems.

Phosphorus runoff from agricultural lands fertilized with animal manures is believed to

play an important role in eutrophication of nearby water bodies. As much as 90% of the P in

runoff from pastures is in the soluble form (Edwards and Daniel, 1993). Soluble reactive P

(SRP) is the most readily available form of P for algal uptake (Sonzongi et al., 1982). Many

state and federal agencies are regulating animal manure applications due to P runoff associated

with high soil test P levels and annual manure applications.

Research has shown that the addition of aluminum sulfate (alum) to poultry litter reduced

ammonia volatilization by 99% compared to normal litter (Moore et al., 1996). Alum-treated

litter has also been shown to reduce P runoff by 87% when compared to untreated litter (Shreve

et al., 1995). Since swine manure is normally a liquid, alternatives to land application such as

composting, pelletizing and transporting are simply not feasible. Therefore, chemical

precipitations of P in swine manure seems to be a feasible solution.

Smith et al. (2001) found that alum and aluminum chloride additions to swine manure

resulted in 84% reductions in SRP runoff concentrations. Although alum can be used to reduce

soluble P and P runoff from pastures receiving swine manure, aluminum chloride is probably a

better choice. This is due to concerns of hydrogen sulfide gas formation in certain situations

with alum additions. Production of hydrogen sulfide gas will not occur with the addition of

aluminum chloride. Smith et al. (2001) concluded that treating swine manure with aluminum

chloride could result in significant reduction in non-point source P runoff from fields fertilized

with swine manure.

All confined animal operations in the state, which utilize a Liquid Animal Waste

Management System, must be permitted by the Arkansas Department of Environmental Quality

(ADEQ) under Regulation No. 5. An important component of each liquid waste system are the

storage structures typically consisting of earthen ponds. Most waste system ponds in the state

are designed for a minimum storage capacity of 120 days of waste water and solids anticipated

from the number of animals confined by the facility. Waste is held in storage until it can be land

applied as a fertilizer, typically to forage crops.

In the fall of 1997, ADEQ Environmental Preservation Division staff conducted a state

wide survey of swine facility waste systems. During this survey, 40 of the approximately 400

swine facilities in the state were randomly selected for sampling and waste characterization.

Van Eps et al. (1998) reported that 52% of the holding ponds sampled were determined to have

draft

46

severe solids accumulation problems. An accumulation of nutrients, including soluble P, was

also found as a result of solid accumulation. In order to reduce waste system related problems

associated with accumulation of solids and the resultant loss of storage capacity, farmers are

encouraged to clean-out their ponds. The waste from these holding ponds will then be land

applied to nearby pastureland. Concerns could result as the sludge is high in nutrients,

particularly P, which could lead to water quality degradation. Smith et al. (2001) found success

in reducing P runoff from plots fertilized with swine flush water treated with aluminum chloride

and aluminum sulfate .However, no studies have observed the effect of aluminum chloride

treatments to swine manure in situ. The objective of this study was to determine the effect of

aluminum chloride on P runoff from swine manure treated in situ.

Methods and Materials Runoff studies were conducted on 24 small plots (1.52 x 6.10 m) cropped to tall fescue on

a Captina silt loam soil (fine-silty, siliceous, mesic Typic Fragiudult) at the University of

Arkansas Agricultural Research Station in Fayetteville, Arkansas. The plots have a 5% slope and

are hydrologically isolated from surrounding land with 15 cm metal borders (inserted so that

approximately 5 cm of the strips were exposed) on three sides. An aluminum collection trough is

located at the downslope edge. Beginning in June of 1999, rainfall simulation studies were

conducted to determine the effects of the following treatments on P runoff: 1) untreated swine

manure (control); 2) swine manure treated with AlCl3 (in situ); 3) swine manure treated with

AlCl3 at the University of Arkansas; and 4)swine manure treated with AlCl3 plus lime at the

University of Arkansas.

The swine manure was collected from a lagoon undergoing total clean out (solids being

removed) near Witt Springs in Searcy County, Arkansas. Initially, the lagoon was agitated for a

minimum of four hours utilizing a Houle Agisprayer powered by a 100 horsepower tractor. After

the first mixing, 500 gallons of untreated waste was collected as the control sample. Thereafter,

1100 gallons of liquid AlCl3 was added to the lagoon as agitation continued. A 15 gallon sample

of the treated waste was then collected from every fifth 3500 gallon Ahoney wagon@ load and

composited into a separate 400 gallon tank. This represented the manure treated with AlCl3 in

situ. Once samples were returned to the University of Arkansas Agricultural Research Center,

100 gallons of the untreated waste was separated for treatment. Treatments 3 and 4 were then

applied at appropriate rates.

Swine manure from the previously discussed treatments was uniformly land applied to

runoff plots as a P base loading rate roughly equivalent to 112 kg P ha-1

(100 lb ac-1

). A 250 ml

subsample of manure applied to each plot was taken for analysis of soluble reactive P (SRP) and

total P. Swine manure was collected in 250 ml centrifuge tubes in situ and placed directly on a

mechanical shaker upon return to the laboratory. The sample was then centrifuged at 8,000

RPM for 20 minutes and filtered through a 0.45 μm and acidified to pH 2 with HCl for SRP

analysis. Soluble reactive P was determined colorimetrically using the automated ascorbic

reduction method (APHA, 1992). Total P was determined using a spectro Model D ICP after

digestion with nitric acid.

After manure application, rainfall simulators were used to provide a 5 cm hr-1

storm

event sufficient in length to cause 30 minutes of continuous runoff. Runoff samples were

draft

47

collected at 2.5, 7.5, 12.5, 17.5, 22.5, and 27.5 minutes after initial runoff. The six samples from

each plot were composited based on flow rates at the time of sampling. Composited runoff

samples were filtered through a 0.45 μm membrane and acidified to pH 2 with concentrated

HCL. Soluble reactive P (SRP) concentrations in the runoff water were determined

colorimetrically on the filtered, acidified samples using the automated ascorbic acid reduction

method (APHA, 1992).

Results and Discussion Mean SRP concentrations in the manure applied were 146, 86.0, 99.6, and 45.2 mg P L

-1

for treatments 1-4, respectively (Figure 1). Untreated swine manure had significantly higher

SRP concentrations among all treatments. All AlCl3 treatments resulted in significantly lower

SRP concentrations. AlCl3/lime additions to swine manure resulted in significantly lower SRP

concentrations than all other treatments. The SRP concentrations in the manure treated in the

lagoon and manure treated at the experiment station with a similar rate were significantly

different. However, the concentrations did not vary greatly from each other. This shows that the

lagoon could have been treated at a rate greater than 1% (AlCl3, v/v), which would result in

lower SRP concentrations. As seen in Smith et al. (2001), AlCl3 additions to swine manure does

lower the SRP concentrations in the swine manure.

Soluble reactive P concentrations for the first runoff event were 29.7, 26.3, 23.4, and

21.3 mg P L-1

for treatments 1-4, respectively (Figure 2). Significantly higher SRP

concentrations in the runoff water found from plots receiving untreated manure than those

receiving manure treated at the experiment station. The lowest P runoff was in the AlCl3/lime

treatment, which also had the lowest manure P solubility. Likewise, the untreated manure

resulted in higher SRP concentrations in the manure and runoff water.

A second runoff event occurred one week after the first runoff event. For the second

runoff event, AlCl3/lime amendments resulted in the lowest SRP runoff concentrations (Figure 3).

Runoff SRP concentrations were significantly lower from plots receiving AlCl3/lime amended

manure than plots receiving unamended manure and manure amended in the lagoon. All runoff

concentrations were lower from the second runoff event than the first runoff event.

Rainfall simulations also conducted 14 and 16 days after the first runoff event occurred.

No significant differences were found among treatments for both events (Figure 4 and 5). As

seen on earlier runoff events, higher SRP concentrations in the runoff water were from plots

receiving unamended manure. Once again, AlCl3/lime amended manure resulted in the lowest

SRP runoff concentrations. As found by DeLaune et al.(2000), higher applications of soluble P

resulted in higher SRP runoff concentrations.

Conclusions

Aluminum chloride additions to swine manure reduced manure P solubility and SRP

runoff concentrations. Aluminum chloride/lime additions to swine manure resulted in the lowest

manure P solubility and runoff SRP concentrations. This is due to the addition of lime to raise

the pH to ensure no Al become soluble, therefore allowing the precipitation of P. Aluminum

chloride additions to the lagoon resulted in significantly lower manure SRP concentrations than

the untreated manure and lower runoff SRP concentrations. These data indicate that addition of

draft

48

aluminum chloride to swine lagoons during clean-out can effectively reduce soluble P levels in

the manure. As a result of reducing manure P solubility, reduction in P runoff from pastures

fertilized with swine manure treated with aluminum chloride can be expected. Further studies

should be conducted to determine the effect of aluminum chloride additions in swine houses in

an attempt to reduce NH3 volatilization and soluble P in the manure. Therefore eliminating the

need to add aluminum chloride to lagoons during clean-out.

References

American Public Health Association. 1992. Standard methods for the examination of water and

wastewater. 18th

ed. APHA, Washington D.C.

DeLaune, P.B., P.A. Moore, Jr., and T.C. Daniel. 2000. Factors affecting phosphorus runoff

from pastures. pp. 51-60. In (J.A. Baaweber, ed.) 2000 proceedings Mississippi Water

Resources Conference. Miss. State Univ.

Donham, K.J. 1996. Air quality relationships to occupational health in the poultry industry. pp.

24-28. In (P.H. Patterson and J.P. Blake, eds.) Proc. 1996 National Poultry Waste

Management Symposium. Auburn University Printing Service, Auburn, AL.

Drummond, J.G., S.E. Curtis, R.C. Meyer, J. Simon, and H.W. Norton. 1981. Effects of

atmospheric ammonia on young pigs experimentally infected with Bordetella

bronchiseptica. American J. Vet. Res. 42:463-468.

Edwards, D.R. and T.C. Daniel. 1993. Effects of poultry litter application rate and rainfall

intensity on quality of runoff from fescuegrass plots. J. Environ. Qual. 22:361-365.

Moore, P.A., Jr., T.C. Daniel, and D.R. Edwards. 1999. Reducing phosphorus runoff and

improving poultry production with alum. Poultry Sci. 78:692-698.

Moore, P.A., Jr., T.C. Daniel, D.R. Edwards, and D.M. Miller. 1996. Evaluation of chemical

amendments to reduce ammonia volatilization from poultry litter. Poultry Science

75:315-320.

Moore, P.A., Jr., T.C. Daniel, D.R. Edwards, and D.M. Miller. 1995. Effect of chemical

amendments on ammonia volatilization from poultry litter. J. Environ. Qual. 24:293-300.

Robertson, J.F., D. Wilson, and W.J. Smith. 1990. Atrophic Rhinitis: The influence of the aerial

environment. British Soc. Animal Production 50:173-182.

Shreve, B.R., P.A. Moore, Jr., T.C. Daniel, D.R. Edwards, and D.M. Miller. 1995. Reduction of

phosphorus runoff from field-applied poultry litter using chemical amendments. J.

Environ. Qual. 24:106-111.

Smith, D.E., P.A. Moore, Jr., C.L. Griffis, T.C. Daniel, D.R. Edwards, and D.L. Boothe. 2001.

Effects of alum and aluminum chloride on phosphorus runoff from swine manure. J.

draft

49

Environ. Qual. 30:992-998.

Sonzongi, W.C., S.C. Chapra, D.E. Armstrong, and T.J. Logan. 1982. Bioavailability of

phosphorus inputs to lakes. J. Environ. Qual. 11:555-563.

draft

50

SR

P c

once

ntr

atio

n i

n m

anure

(m

g L

-1)

0

20

40

60

80

100

120

140

160

A

B

C

D

Control Trt. 1

AlCl3Trt. 3

AlCl3 (in situ)

Trt. 2

AlCl3/Lime

Trt. 4

Figure 1. Soluble reactive P concentrations in manure amended with aluminum chloride

draft

51

SR

P i

n R

un

off

Wat

er (

mg P

L-1

)

0

5

10

15

20

25

30

35

A

AB

BC

C

Control Trt.1

AlCl3 (in situ)

Trt. 2

AlCl3Trt. 3

AlCl3/Lime

Trt. 4

Figure 2. Soluble reactive P concentrations in runoff water from the first runoff event on

amended plots.

draft

52

SR

P c

on

cen

trat

ion

in

ru

no

ff w

ater

(m

g P

L-1

)

0

5

10

15

20

25

A

A

AB

B

Control Trt. 1

AlCl3 (in situ)

Trt. 2AlCl3Trt. 3

AlCl3/Lime

Trt. 4

Figure 3. Soluble reactive P concentrations in runoff water from the second runoff event on

amended plots

draft

53

SR

P c

once

ntr

atio

n i

n r

unoff

wat

er (

mg P

L-1

)

0

2

4

6

8

10

12

14

Control Trt. 1

AlCl3 (in situ)

Trt. 2

AlCl3Trt. 3

AlCl3/Lime

Trt. 4

Figure 4. Soluble reactive P concentrations in runoff water from the third runoff event on

amended plots

draft

54

SR

P c

once

ntr

atio

ns

in r

unoff

wat

er (

mg P

L-1

)_

0

2

4

6

8

10

12

Control Trt. 1

AlCl3 (in situ)

Trt. 2

AlCl3Trt. 3

AlCl3/Lime

Trt. 4

Figure 5. Soluble reactive P concentrations in runoff water from the fourth runoff event on

amended plot

draft

55

VIII. Conclusions

The Land Application of Accumulated Solids From Liquid Waste Systems Demonstration

Project was a success in that it has helped to raise producer, integrator, and government

awareness of manure solids accumulation issues and how they can be properly addressed. As

this project progressed, the interest in proper operation of swine liquid animal waste management

systems (LAWMS) has dramatically increased on the part of the swine industry and government

agencies charged with regulating and providing technical assistance to Arkansas swine farmers.

The interest in proper swine manure management generated by this and preceding projects has

helped to bring assistance to operators of facilities requiring LAWMS clean-outs in the form of

financial assistance for the execution of properly planned system clean-outs.

Through this project, the solids accumulation issue associated with LAWMS has been brought to

the attention of swine industry and government, unfortunately producer participation in the

project was less than hoped for. The reasons for the lack of farmer participation varied,

however, ultimate interest in cleaning-out swine LAWMS must come from the producer or be

driven by industry or legislation. Every LAWMS operator in the state was made aware of the

solids accumulation issue through multiple presentations at Regulation 5 training meetings and in

most cases farmers understand and have an interest in the issue. In addition to producer wariness

of government agencies and programs, the most likely reason for not wanting to participate in

obtaining a plan for a total pond clean-out was cost. Federal cost-share assistance for properly

planned LAWMS clean-outs will increase farmer interest in completely emptying out

accumulated solids from their systems.

Financial assistance for LAWMS clean-outs should be provided to farmers only if there is a plan

developed specifically for that facility that will be protective of water quality. The planning

criteria must take into account mass of accumulated nutrients, soil test phosphorus values,

reducing over-application of phosphorus by applying at one-half the nitrogen rate, potential

BMPs including pasture renovation and stormwater diversion, and continuous management of

the system after the clean-out has been completed.

At this time, the potential exists that permit holders of LAWMS will be required to document

and provide verification that the system has been cleaned-out every year as part of the annual

reporting process. If the requirement to document annual pond clean-outs comes to fruition, the

resources for providing proper planning and clean-out services will need to be developed in order

to accommodate the number of facilities that will require the initial pond clean-out of years

worth of accumulated manure solids.

An additional condition that has recently developed in Arkansas, is the announcement by a major

pork production integrator that the company will no longer contract with Arkansas pork

producers. The result of this action is that approximately 140 swine facilities will no longer be in

operation. Of the 140 facilities, many owners of those facilities will elect to close out their

permits. This will be another situation that will require additional resources to address the

number of facilities that will require manure solids clean-out planning. Failure to provide proper

planning and oversight will result in deleterious effects on water quality, especially in areas with

draft

56

high densities of swine production facilities.

A total of 18 farmers requested and received planning assistance through the framework set up in

this project. Each farmer received help in assessing the solids and nutrient accumulation status

within their LAWMS and were given recommendations on how to proceed in recovering the full

waste system storage capacity while achieving the greatest fertilizer benefit and protecting water

quality. Farmers that followed the recommendations in the farm specific plan reduced the

environmental impacts of their system by reducing the over-application of N and P as well as

reducing the potential for future pond discharges.

Many farmers had difficulty in immediately implementing the clean-out plan. This was

primarily due to insufficient monetary resources and a lack of available permitted land

application acreage to assimilate the mass of nutrients in storage. Future planning will need to

acknowledge that for most farms, a multi-year approach will be required to accomplish the task.

This will allow the farmer time to plan for the clean-out expense in his operating budget.

Another major hurdle in implementing the plans involved the amount of available land

application acreage. Of the 18 participating farms, 16 required additional acreage to accomplish

the task in a manner that satisfied project goals of applying the mass of nutrients at acceptable

environmental and agronomic rates. However, the regulatory framework for adding land

application acreage to a permit is by design difficult, time consuming and relatively expensive.

From an environmental stand point, the manure can be better assimilated by soil and cover crops

when spread over a greater area. In many ways, animal manure is a better soil amendment than

commercial fertilizer, however, regulatory restrictions and negative public attitudes serve to limit

more widespread use. The industry practice of concentrating large numbers of farms in relatively

small geographic areas has contributed to negative public perception of manure as a fertilizer and

has contributed greatly to contract grower difficulties in adequately managing manure. An

associated farm density issue is forest conversion to pasture in order to obtain more acreage on

which to land apply manure. Forested land can benefit farms by providing visual barriers, aid in

dispersing odors and associated gases and moderating seasonal temperature extremes. That

being said, farmers should be encouraged by all parties to utilize land that has already been

converted to pasture, rather than clearing additional forest merely to increase the available land

application acreage.

As farmers realize the benefits of accumulated manure solids removal, including less time spent

on system maintenance and greater fertilizer value derived from animal manure, and at the same

time, more resources become available for planning and financing clean-outs, the number of

clean-outs occurring in the future should increase significantly. System clean-outs in watersheds

that have a large number of facilities should be monitored to insure that the number of facilities

performing clean-outs during any one period do not exceed that capacity of the watershed to

assimilate the land applied nutrients. For example, in the Millwood Lake watershed, in the

southwest part of the state, there are approximately 100 swine facilities. If in the worst case, all

of those facilities were to perform a system clean-out at the same time, land applying hundreds

of thousands of pounds of nutrients, the potential exists for significant adverse effects on the

water quality of Millwood Lake, including algae bloom and low dissolved oxygen conditions.

The timing and number of LAWMS clean-outs should be monitored to avoid over-loading a

watershed with nutrients.

draft

57

Thorough planning is only half of the process for an environmentally responsible LAWMS

clean-out. As good as any plan may be, it is only as good as the person actually performing the

clean-out. Since most facilities do not have adequate equipment to carry out the mixing and

removal of accumulated solids, many operators will be utilizing contract pumping services.

Each clean-out that is conducted by contracted services should be monitored, at least in part, by a

person who is familiar with the plan for the LAWMS clean-out and the land application of

animal manures. It is foreseeable that unscrupulous service providers would not follow plans to

avoid spending the extra time required to land apply the liquid manure at rates specified in the

plan. Improper land application of the manure solids not only affects water quality, it affects the

producer by under utilizing the fertilizer value of the removed solids and causing phosphorus

accumulation in pastures that may result in those pastures becoming unsuitable for land

application of manure in the future. In addition, nitrogen toxicity to cattle consuming over-

fertilized forage could be a concern. Some method of accountability should be developed to

avoid improper land application practices by pump out services.

The use of Aluminum Chloride additions to swine manure showed effectiveness in reducing the

amount of soluble phosphorus in accumulated manure solids as well as reducing the amount of

soluble reactive phosphorus concentrations in simulated runoff conditions. Aluminum

chloride/lime additions to swine manure resulted in the lowest manure phosphorus solubility and

soluble reactive phosphorus concentrations in simulated stormwater runoff. The data collected

as part of this project indicate that addition of aluminum chloride to swine lagoons during clean-

out can effectively reduce soluble phosphorus levels in the manure. As a result of reducing the

quantity of soluble phosphorus during the clean-out, reductions in phosphorus runoff from

pastures fertilized with swine manure treated with aluminum chloride would be expected. An

amount of aluminum chloride equivalent to one percent of the volume of sludge was added to the

test LAWMS at a cost of approximately $2,000 for a relatively small system (200,000 gallons).

Although the addition of aluminum chloride did reduce the amount of soluble phosphorus in the

system, it is questionable as to whether or not this is a cost effective solution to reduce

phosphorus runoff. This treatment method could possibly be used as a last resort in situations

where a producer, that has high soil test phosphorus levels and has no viable means to obtain

additional acreage that is within a reasonable hauling distance from the facility, needs to perform

a system clean-out to continue operation or to complete a system closure. Further studies should

be conducted to determine the effect of aluminum chloride additions in swine houses in an

attempt to reduce ammonia volatilization and soluble phosphorus in the manure, eliminating the

need to add aluminum chloride to lagoons during clean-out.

The compilation of additional analytical data from properly sampled manure storage ponds at

cooperating farms has been a significant accomplishment of the project. Along with information

obtained through the Swine Project and the Solids Survey, this data forms an important base of

information that can be used in a variety of ways to improve waste system design, operation and

maintenance. The analytical data may find use in the future as a planning tool for LAWMS

clean-outs. For example, using the volume of solids present in a system, easily determined by

measuring the solids depth and using the storage pond design plans, the mass of nutrients may be

predicted by multiplying the average concentration of nutrients in manure solids collected during

this project by the volume of solids estimated to be in the pond of interest. The data collected

draft

58

through this project could provide much needed supplementary information for the design and

maintenance of LAWMS. The utility of the data that has been collected during the course of this

project illustrates the value this project has provided to taxpayers.

Until tools to estimate the quantity of nutrients contained in a LAWMS are available, accurate

pond sampling should be conducted utilizing a protocol similar to that described in this report. It

is unlikely that producers will have the resources to execute the type of sampling necessary for

accurate manure clean-out planning and resources, in the form of assistance from local

conservation districts, the Cooperative Extension Service or a private vendor will be required.

During the course of this project the concept of managing animal manure with forethought and

insight has been presented to a broad range of people involved in the pork production industry in

Arkansas. The ultimate success of this project can be evaluated in short and long term results.

In the short term, this project was able to assist a number of swine facilities address accumulated

swine manure solids in a cost-effective and environmentally responsible manner. In the long

term, the project has helped to generate an interest within agencies responsible in assisting the

small swine farmer that should perpetuate some of the ideas developed through the work of this

project. Ultimately, it is hoped that this project has helped to insure that small family farms can

remain viable and sustainable, maintaining diverse and vibrant rural economies, while protecting

water resources for years to come.

draft

59

References

1 U.S. Environmental Protection Agency, “1996 National Water Quality Inventory Report to Congress,”

Washington, D.C., 1998 2 Arkansas Department of Pollution Control & Ecology. 1992. Regulation No. 5 Liquid Animal Waste

Management Systems. Open File Report prepared pursuant to the Arkansas Water and AirPollution Control

Act (Act 472 of the Acts of Arkansas for 1949). 10 pp. 3 S. J. Formica, T. Morris, M. A. Van Eps, T. Kresse, M. Anderson, J. Giese, Using Data, Communication &

Education to Improve Swine Waste Management in the Buffalo River Watershed, from the proceedings of

the 2nd National Conference on Nonpoint Source Pollution Information & Education Programs, Chicago,

Il, May 15-17, 2001 4 USDA NRCS, Part 651 Agricultural Waste Management Field Handbook, Page 3-12, 1992

5 Reed, Benjamin, Effect of Pasture-Applied Swine Slurry on Runoff and Leachate Water Quality, University of

Arkansas, 1996 6 Van Eps, S. Formica, T. Kresse, A. Czarnomski, E. Van Schaik, J. Giese, T. Morris, from the proceedings of the

“International Conference on Agricultural Engineering” Oslo, Norway August 24 - 27, 1998 7 USDA NRCS, Part 651 Agricultural Waste Management Field Handbook, Page 4-12, 1992

8 ADEQ, Environmental Preservation Division, Sandi Formica, Principle Investigator, Administered by Arkansas

Soil and Water Conservation Commission, Project FY99-600

land application of accumulated solids from liquid waste ... application report.pdf · land...

Documents