P.A.Vinoth Kumar ( BTG-12-039 )D.Vijaya Sowmiya ( BTG-12-038 )S.Vignesh ( BTG-12-037 )

Treated Wastewater for

Irrigation

Presentation8/6/15-Monday

1. Topic Analyzing

2. Objectives

3. Farm Level & Evaluation of WW

4. Permit Requirements

5. Quality of Wastewater

6. Irrigation Methods

7. Conclusion

8. Reference

Topic Analyze• Irrigation with municipal wastewater is a suitable

disposal option in all regions where additional

moisture can be effectively utilized for improved crop

production. Wastewater loading is to be based on the

consumptive water use of the crop being grown.

• The primary objective should be enhancement of crop

production. The root zone of productive soils can often

serve as one of the most active media for the

decomposition, immobilization, or utilization of wastes.

Objectives• To avoid wastewater discharge across privately-owned lands or into intermittent watercourses.

• As an alternative to nutrient or phosphorus removal, where required.

• As an alternative to exceptionally high treatment requirements.

• To provide a water supply for food crops, non-food crops and golf course irrigation.

Farm Level•  The required amount of water should be applied.

• The water should be of acceptable quality.

• Water application should be properly scheduled.

• Appropriate irrigation methods should be used.

• Salt in the root zone should be prevented by means of leaching.

• The rise of water table should be controlled by means of appropriate drainage and Plant nutrients should be managed in an optimal way.

When Evaluating wastewater for irrigation use

• Identify physical, biological, and chemical

constituents that may be a potential environmental

or health-based concern.

• Development of appropriate protocols for

determining land areas that are suitable to receive

municipal wastewater for irrigation.

• Determination of the appropriate annual

wastewater loading rates, the frequency, duration

and method of application, as well as the period

over which such applications can occur.

• Inclusion of a process that will ensure there is

appropriate technical review of valid neighborhood

stakeholder concerns.

Permit Requirements• Permit to construct, extend or alter any treated

wastewater irrigation works must be obtained from the Water Security Agency (WSA) before starting construction of such works. • Treated wastewater irrigation projects may will require a

hydrogeological investigation based on irrigated volumes and long-term effects on soil and groundwater. • Soil certification and an assessment of long-term soil and

groundwater effects will be required. The water table in the irrigation area must be sufficiently deep to prevent water table rise to the root of the plants.

Design GuidelinesWastewater TreatmentThe minimum treatment requirement as per Guidelines for Sewage Works Design (EPB 203) shall be as follows: • Lagoons followed by a storage cell of holding

at least 210-230 days of sewage flow. • Secondary treatment with adequate storage

facilities.• Disinfection may be required prior to

irrigation based on the type of reuse.

Soils & Topography• The chemical, physical and morphological

characteristics of a soil must be compatible to irrigation with a particular wastewater. It is important to minimize soil degradation to ensure that lands irrigated with treated wastewater benefit from irrigation and will retain productivity. The soil should not receive harmful quantities of undesirable elements and substances. • The physical properties of soil texture and structure are

important features when evaluating the use of treated wastewater for irrigation. Careful consideration should be given to permeability, since the suitability of soil for irrigation depends on the ability to conduct air and water.

Natural Irrigation Water Quality Characterization

• Electrical conductivity (EC): Is a reliable indicator of the total dissolved solids content of the water. The addition of irrigation water to soils adds to the concentration of salt in the soil. Concentration of these salts will result in an increase in osmotic potential in the soil solution interfering with extraction of water by the plants. Toxic effects may also result with an increase in salinity. EC is measured in ds m-1

• Sodium Adsorption Ratio (SAR): Is an indicator of the sodium hazard of water. Excess sodium in relation to calcium and magnesium concentrations in soils destroys soil structure that reduces permeability of the soil to water and air. Sodium may be toxic to some crops.

• Boron - Toxicity due to specific ions such as boron occurs when the ion is taken up by the plant and accumulates in the plant in amounts that result in damage or reduced yields. Discharges from industrial plants and household detergents are the common source for boron in wastewater; other ions of most concern in wastewater are sodium and chloride.

The General parameters are those that are analyzed to assess the effectiveness of the wastewater treatment process and to evaluate variability in the quality of the wastewater prior to its release to the environment.

• Biochemical Oxygen Demand (BOD) typically ranges from 10 to 20 mg/L for most municipal wastewaters. Values below 100 mg/L pose no restriction to irrigation use.

• Total Suspended Solids (TSS) typically ranges from 10 to 20 mg/L for most municipal wastewaters. Values below 100 mg/L pose no restriction to irrigation use.

• Chemical Oxygen Demand (COD) typically ranges from 25 to 50 mg/L for most municipal wastewaters. Values below 150 mg/L pose no restriction to irrigation use.

• pH typically ranges from 6.5 to 8.5 for most municipal wastewaters. These values are comparable to most natural surface waters and are considered to pose no restriction to irrigation use.

Irrigation Methods

• Flood irrigation - water is applied over the entire field to infiltrate into the soil (e.g. wild flooding, contour flooding, borders, basins, etc.).

• Furrow irrigation - water is applied between ridges, water reaches the ridge, where the plant roots are concentrated, by capillary action.

• Sprinkler irrigation - water is applied in the form of a spray and reaches the soil very much like rain (e.g. portable and solid set sprinklers, travelling sprinklers, spray guns, center-pivot systems, etc.). The rate of application is adjusted so that it does not create ponding of water on the surface.

Many different methods are used by farmers to irrigate crops. They range from watering individual plants from a can of water to highly automated irrigation by a Centre pivot system.

• Sub-irrigation - water is applied beneath the root zone in such a manner that it wets the root zone by capillary rise (e.g. subsurface irrigation canals, buried pipes, etc.)Deep surface canals or buried pipes are used for this purpose.• Localized irrigation - water is applied around

each plant or a group of plants so as to wet locally and the root zone only (e.g. drip irrigation, bubblers, micro-sprinklers, etc.) The application rate is adjusted to meet evapotranspiration needs so that percolation losses are minimized.

Conclusion• In this respect National and International

Institutions, universities and research centres have an important role in both research and training needed for a safe and efficient wastewater use for agriculture.

• The goal of such joint work should be also directed towards the establishment of successful networks categorized according to their purposes which range from information exchange to collaborative planning, implementation and monitoring of research activities in the field of unconventional water resources.

Reference• Alberta Environmental Protection, 1997. Standards and

Guidelines for Municipal Waterworks, Wastewater and Storm Drainage Systems. Edmonton, Alberta.

• Alberta Agriculture, Food and Rural Development (AAFRD). 1999. Standards for the Classification of Land for Irrigation in the Province of Alberta. Lethbridge.

• American Society of Agronomy. 1965. Methods of Soil Analysis Part 1, Agronomy

• Agriculture Canada Research Branch. The Canadian System of Soil Classification.

• 1st edition (1978), 2nd edition (1987) and 3rd edition (1998) Publication #1646.

Thank You