surviving the local wip: a practical guide on nutrient accounting for the chesapeake bay tmdl

Surviving the Local WIP:a practical guide on

nutrient accounting for the Chesapeake Bay

TMDL

Contact Info

Tom Schueler

Chesapeake Stormwater Network andEPA Chesapeake Bay Program Stormwater

Coordinator

Baltimore, MD

watershedguy@hotmail.comwww.chesapeakestormwater.net

www.cbstp.org

Key Topics

• Some nutrient math • Some basics on the Bay TMDL • 12 easy steps to comply with your

local load allocation • Discussion

Technical Bulletin # 9Nutrient Accounting Methods to Document Local

Stormwater Load Reductions in the Chesapeake Bay

• Nutrients and the Chesapeake Bay• Why we need to become nutrient accountants• What we know about nutrients and stormwater• Tools to estimate nutrient loads• Defining the local baseline load• Pollutant removal rates for urban BMPs *• Strategy for achieving local load reductions• Analyzing the cost of implementation

* official CBP rates and proposed interim planning rates

Urban NutrientsWhere do they come from?

There are many sources of N and P in the urban environment

Relationship of Atmospheric Deposition to Urban Runoff Quality

NutrientAtmospheric Deposition 1

Stormwater Runoff Load 2

Pounds per impervious acre per yearTotal Phosphorus 0.7 2.0Total Nitrogen 13 to 17.0 15.41 measured rates during Washington NURP Study (MWCOG, 1983)2 Simple Method annual stormwater runoff loads for one acre of impervious cover (Schueler, 1987)

Much of the nitrogen in urban runoff is derived from atmospheric deposition, either in the form of dryfall or wetfall

Other sources of nitrogen in urban runoff include:

• Washoff of fertilizers• Nitrogen attached to eroded soils and streambanks • Organic matter and pet wastes on IC

What we know about turf and its management in the Bay Watershed

• 3.8 million acres of turf• Represents 9.5% of watershed area• Exceeds area devoted to row crops (corn, wheat, soybeans)• 75% of turf is home lawn

Nitrogen EMCs for different urban land covers

Urban Land Cover Total N (mg/l)

Lawns 9.70

Highway 2.95

Streets (Variable) 1.40

Parking Lots 1.94

Rooftops 1.50

Source; CWP, 2003

Runoff sampling shows that lawn runoff is very high in nitrogen. Also, rooftop runoff concentration shows effect of atmospheric deposition

About 50% to 65% fertilize their yard

15 to 20% hire lawn care company

Average of two applications per year

50% of homeowners over-fertilize

Estimated N Fertilizer inputs by lawns: 215 million lbs/yr

What do we know about home lawns and nutrients?

What have you been hearing about the Chesapeake Bay TMDL ?

Bottom Line of Chesapeake Bay TMDLFor Urban Suburban Sector

~25 to 30% TP and TN load reductions needed from existing development (plus sediment reductions)

No increase in future load as a result of growth and development

60% of the reductions to be achieved by 2017

100% by 2025

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Some folks think the WIP process is scary

• Billions in potential costs• Short planning horizon (draft plan due Dec 1, 2011)• Potential regulatory liability • High planning costs • Lots of complex documents

= major local headaches

The WIP Process is not as Scary as it Looks

• Each state works with its local governments to develop strategies for nutrient reduction

• The jurisdictional unit could be a MS4 permitee, planning district commission, county or conservation district, depending on the state

• The liability for not meeting the load reductions is a state liability, and not a local one (unless tied into MS4 permit)

What to expect:

• Locals will need to submit data, have a strategy and report on BMP implementation

• Locals will need to follow state and/or CBP approved procedures for tracking and verifying BMPs

• States have the responsibility for aggregating local data and submitting it to EPA to show progress in load reductions

The WIPs are a long term process

• Progress is assessed based on two year milestones

• Implementation of the WIP is a 15 year iterative process

• Many opportunities for adaptive management and collaboration

Check with your state agency to find who is responsible for WIPs in your state and the process they will follow

(they differ a lot)

A practical local strategy to meet the local WIP

BMP Credit Lead Agency Other Stakeholders

Watershed Mapping/Planning Planning, GIS Local watershed group

Stormwater Retrofits DPW or stormwater review agency

Schools, parks, roads, and other public land

New Development Stormwater review agency Land use planning

Maintenance Upgrades DPW Maintenance crew CIP budgets

Stream Restoration Environmental resources Parks

Redevelopment Credits Stormwater review staff Planning agency

Reforestation Community forestry andSite planning agencies

Parks, street trees, schools

Street Sweeping DPW Maintenance Crew Street maintenance

Urban Fertilizer Management MS4 Permit holder Cooperative Extension

Septic Hookups/Upgrade Sanitarian wastewater Utility

Illicit Discharge Elimination MS4 Permit holder Watershed groups

Wetland/shoreline Restoration Local environmental agency

Land conservancy

Step 1 Organize a local watershed implementation team

Initial Tasks for the Watershed Team

• Obtain the local nutrient reduction allocation from the state or regional agency administering the TMDL

• Coordinate with the state TMDL agency to better understand their local expectations 

• Analyze local land use and land ownership data to determine what part of their load allocation can be legitimately excluded 

• Identify which local agencies or stakeholders have primary responsibility to implement the dozen available urban BMP credits

• Check to see if agencies are already implementing a credit, or could do so through modest changes to existing programs.

• Determine how the credits should be documented and reported to the appropriate state or regional agency

# 2 Take credit for fertilizer reductions on urban turf

• Reflects recent MD and VA P Ban in Fertilizer

• Modeled as an application reduction, with an estimated 17 to 19% TP reduction in urban loads

• Research in other regions put it closer to 10 to 12%

• TN reductions are minor unless regional education campaign program to reduce N fertilization

Right now, none of our residential stewardship programs focuses on reducing urban fertilizer use, despite the fact it is the most cost effective nutrient reduction strategy

• 1.5 million acres of home lawn are fertilized

• Very limited incentives beyond free soil testing and passive technical advice • We send conflicting messages to homeowners about lawn fertilization

Urban NitrogenFertilizer Reduction

Fertilizer Message 1 • Get a soil test, and if adequate P is

present, then select P-free fertilizer

• Calibrate your spreader

• Follow label directions of weed/feed products

• Use slow release N fertilizer in Fall only

• Apply 1 to 4 lbs of actual N per 1000 square feet

• Do not apply to frozen soils, impervious cover or in advance of a thunderstorm

• Use a composting lawn mower and recycle composted leaves over yard

• Set mower height at three inches

• Irrigate only after extended drought

• Don’t washout your spreader over IC

Fertilizer Message 2

Tommy makes an offer you can’t refuse!

• Keep your spreader in the garage for the next three years to protect the Bay

• Save 150 bucks and three weekend days

• If you still like the look of your lawn after three years we will buy back your spreader for $150

• If you think your lawn looks like crap, we will pay for a lawn makeover worth $500 (using our green lawn service)

The Competing Fertilization Message

Consumer surveys indicate the primary and almost exclusive sources for information on fertilizing their lawns are:

• TV and radio commercials

• Product labels in the big box store

• Store attendants

• Recommendation from their lawn care company

# 3 Take nutrient reduction credits for more stringent stormwater requirements at redevelopment projects

• Calculate the expected acres of impervious cover slated for redevelopment

• Estimate the runoff capture volume and design level using new regs

• Calculate the aggregate nutrient reduction credit

Nutrient Reduction Credits for RedevelopmentLbs/acre/year

NutrientRainfall depth for which stormwater treatment is computed (inches)

0.25 0.50 0.75 1.0 1.25 1.5LO1 HI2 LO HI LO HI LO HI LO HI LO HI

Total P 0.4 0.6 0.6 0.9 0.75 1.1 1.0 1.5 1.25 1.65 1.4 1.8

Total N 3.3 4.5 5.1 6.8 6.3 8.4 8.4 11.3 9.9 12.3 11.1 13.5

Multiply aggregate acres of redeveloped IC by the per acre load reduction credit

Can be an important strategy in several Bay cities

# 4 Become an Early Adopter of Stormwater Regulations

This ensures that your nutrient liability won’t continue to increase

Variability in Bay State Stormwater Regulations

• Considerable confusion in terminology among the states (ESD, LID, RR, treatment trains)

• Each state/locality is on a different schedule for implementing them (2009 to 2013)

• Each state has a unique hydrologic performance standard

• Differential standards for new and redevelopment• Individual sites may not fully comply with

standard

Will the new standards lead to nutrient neutrality for new development projects in the future ?

TP Loads, By Land Based Sector in Maryland Bay TMDL

Loading Sector 2009 Load Target Load

Million pounds per year

Forest Runoff 0.35 0.35Urban and Suburban Runoff

0.67 0.44

Agricultural Runoff 1.44 1.25ALL RUNOFF SOURCES 2.46 1.99 3

Acceptable Load (lbs/acre) 0.56 0.34excludes CAFO portion of agricultural runoffWastewater sources excluded

Same Analysis Yield an Acceptable TN Load of 4.4 lbs/acre

Results differ slightly for each state based on distance to the Bay

What is an acceptable runoff nutrient load?

What local safeguards are needed to ensure the load limits are actually achieved on the ground?

Practices designed in accordance with Bay-wide Design Specs

Post-construction certification that it was installed properly and works

Municipality meets minimum performance standards for:

ongoing performance inspections maintenance enforcement

• Set goal to reforest 5% of current turf cover

• 10 to 1 Rule (ten acres of reforestation equals one acre of impervious cover treated)

• CSN and VADCR spreadsheet rates are about the same

• Get extra credit for•Treating runoff from adjacent IC • Stream or shoreline buffer upgrades ?

# 5 Take Credit for Community Reforestation

# 6 Take credit for current and future stream restoration projects

• High nutrient reduction rates for qualifying projects• Provides both a local benefit and a Bay benefit• Generally popular with the public• Cost competitive with pond retrofits

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Proposed Interim Stream Restoration Rate

Removal rate per Linear foot of Qualifying Stream Restoration Source TN TP TSS

CBP 2005 N=1

0.02 lbs 0.0035 2.55 lbs

CSN 2011 N=6

0.20 lbs 0.068 lbs 310 lbs

U of MD StudyN=25+

Scheduled for early 2012

CBP BMP Panel to Update Stream Restoration Rates

• U of MD Literature Review• Review of 20 + studies on various parts of the urban stream nutrient cycle• Develop concept model for predicting rates• Should be done by early 2012

What’s a Qualifying Project?

Can’t just dump rip-rap

Comprehensive stream design

Flood plain re-connection

Minimum reach size

In-stream habitat features

# 7 Re-tool your stormwater maintenance program

Inspect the performance of your existing BMP inventory

Field Research Indicates about 30% of the BMP Inventory needs a makeover

Significant nutrient reductions are possible through these low cost “BMP makeovers”

Performance downgrades must be reflected in local WIP baseline load

By Retooling existing Maintenance Budget, it is possible to eliminate eyesores and clean the Bay

Thirty Years of BMPs. The BMP Inventory in a Maryland County

Potentially High Performers Known Low Performers

Bioretention/Dry Swales

49 Underground Detention

270

Sand Filters 279 Dry Ponds 528

Wet pond 212 Oil Grit Separators 805

Pond Wetland 98 Proprietary Practices

239

Infiltration Basin 58 Flow Splitter 321

Infiltration Trench 459 Other (plunge pools) 30

Adapted from MCDEP 2006 3350

Dealing with the Local BMP Legacy

# 9 Take the Mass Credit for Intensive Street Sweeping

• New CBP Method based on Actual Pollutant Mass Picked Up• Qualifying Frequency and Technology• Incentive for Sweeping Crews to Maximize Pickup

# 9 Investigate Septic Hookups and Upgrades

• Key Strategy for TN removal • Relict septics in sewered

catchments• Upgrade N technology in

existing septics• Sewer extensions and

cluster satellites • CBP Rates available

# 10 Take Credit for Eliminating Illicit Discharges

• For chronic and episodic sewage discharges that are physically eliminated

• Reduction based on rate of dry weather flow and outfall concentration above background levels

• CWP research indicates this can be an important strategy in some urban watersheds available

Source: CWP

# 11 Retrofit Existing Stormwater Ponds

# 12 Residential LID Retrofits

Subsidies, technical assistance, stormwater utility credits and other incentives to build LID retrofits on private land

The Cost Challenge

The weakest link in local WIPs are accurate cost data for practices

Need to acquire better cost data and share it

Possibility of Bay-wide database

Millions vs. billions

Discussion: