ANIONIC POLYACRYLAMIDE (PAM) EROSION …

1 450 - 1 NRCS, NHCPM arch 2001 Conservation practice standards are reviewed periodically, and updated if needed. To obtainthe current version of this standard, contact the Natural Resources conservation RESOURCES CONSERVATION SERVICECONSERVATION PRACTICE STANDARDANIONIC POLYACRYLAMIDE (PAM) EROSION CONTROL(Acre)CODE 450 DEFINITIONE rosion control through application of water -soluble ANIONIC POLYACRYLAMIDE (PAM).PURPOSEThis practice is applied as part of a conservationmanagement system to support one or more ofthe following: Minimize or control irrigation-induced soilerosion. Reduce wind and/or precipitation EROSION . CONDITIONS WHERE PRACTICE APPLIES On irrigated lands susceptible to irrigation-induced EROSION , excluding peat soils, andwhere the sodium adsorption ratio (SAR) ofirrigation water is less than 15; On areas where the timely establishment ofvegetation may not be feasible or wherevegetative cover is absent or inadequate; On areas where plant residues areinadequate to protect the soil surface fromwind EROSION ; and On sites where disturbance activities preventestablishment or maintenance of a covercrop; This standard does not apply to the application ofpolyacrylamides to flowing, non-irrigation, waters.

2 CRITERIA General Criteria Applicable To All Purposes Changes in management shall be implementedwhere increases in soil infiltration rates are aresult of implementing this practice. The POLYACRYLAMIDE (PAM) shall: be of the ANIONIC type meeting acrylamidemonomer limits of percent (%), have a charge density of 10 to 55%, byweight have a molecular weight of 6 to 24 Mg/mole. be mixed and/or applied in accordance withall Occupational Safety and HealthAdministration (OSHA) Material Safety DataSheet requirements and the manufacturer srecommendations for the specified use. conform to all federal, state, and local laws,rules, and regulations. Additional Criteria Applicable To IrrigationInduced Soil EROSION Surface Irrigation PAM shall be used during the first irrigation andafter any soil disturbance (pre-irrigation isconsidered irrigation) and during later irrigations ifsoil movement is observed.

3 Mixed concentrations of PAM shall be added toirrigation water only during the advance phase of asurface irrigation. The advance phase shall beconsidered the time irrigation starts until waterhas advanced to the end of the field. Dry or patch treatments of PAM shall be placedover an area of the first five (5) feet of - 2 NRCS, NHCPM arch 2001 The resulting concentration of PAM in irrigationwater shall not exceed 10 ppm of pure formpolyacrylamide, applied on a total product basis. Sprinkler Irrigation The maximum application rate of Polyacrylamideactive ingredient shall not exceed four (4) poundsper acre (lb/ac) per single application event. PAM mixtures will be totally mixed and liquefiedprior to injection into the irrigation system.

4 Injection shall occur on the downstream side of allscreens and/or filters and conform to all federaland state chemigation standards. Additional Criteria Applicable To ReduceWind and/or Precipitation EROSION The maximum application rate of pure formpolyacrylamide shall not exceed 200 lb/ac peryear. Emulsion batches shall be mixed with pure formpolyacrylamide not exceeding 200 pounds perbatch. Application method shall insure uniform coverageto the target area, minimizing drift to non-targetareas. CONSIDERATIONS The following relate to the application of thepolyacrylamide practice that may enhance, oravoid problems with the practice but are notrequired to insure its basic conservation function. General PAM application rates may need to be adjustedbased on soil properties, slope, and type oferosion targeted.

5 Where reasonably possible, tailwater or runoffcontaining PAM should be stored for re-use orrecycled on other land areas. Use of POLYACRYLAMIDE in combination with otherconservation and Best Management Practices willimprove EROSION control. Irrigation Induced EROSION Considerations Other conservation treatments such as landleveling, irrigation water management, reducedtillage, reservoir tillage, crop rotations, etc. shouldbe used in conjunction with this practice tocontrol irrigation-induced EROSION . PAM may result in an increase in surfaceirrigation infiltration of up to 60%, with 15% beingtypical on medium textured soils. To compensate for PAM changes in infiltration,adjustments in flow rates, time of set, and tillagepractices should be considered.

6 Adjustment from maximum PAM rates andvolumes should be considered so long as novisible EROSION occurs. Secondary applications on undisturbed soil maybe needed in surface irrigation when sediment orerosion is noted. Sprinkler systems will likely need multipleapplications to achieve a significant erosionreduction. For sprinkler systems, before and after injectingconcentrated liquid PAM (30 to 50% activeingredient) into sprinkler irrigation systems, it is agood practice to pump a surfactant (crop oil)through the injection system (pump, tubing,valves, etc.). Surfactants provide a buffer betweenPAM and water so non-flowing PAM does notcontact water and form a gelatinous mass thatcan plug valves and tubing.

7 For sprinkler injection, the injection pump shouldbe started after water is flowing in the sprinklersystem and stopped when the irrigation pumpstops. Applications at the end of the season arediscouraged, unless the field has been recentlytilled. Wind or Precipitation EROSION Considerations Adding seed to POLYACRYLAMIDE mixture mayprovide additional EROSION protection beyond thelife of the PAM material. PAM may improve water quality, infiltration, soilfertility, and air quality. Safety and Health Use proper personal protective equipment, , masks, and other health and safetyprecautions in accordance with the label,industry, and other federal or state rules - 3 NRCS, NHCPM arch 2001 If inhaled in large quantities, PAM dust can causechoking and difficulty in breathing.

8 Personshandling and mixing PAM shall use a dust maskof a type recommended by the manufacturer. PAM solutions can cause surfaces, tools, etc. tobecome very slippery when wet. Clean liquid PAM spills with dry absorbentmaterial (sawdust, soil, cat litter, etc.) andsweep/collect dry PAM material without washingwith water . PLANS AND SPECIFICATIONS Specifications will be developed site specificallyfor each application. Specifications for thispractice will be prepared for each field ortreatment unit according to the criteria,considerations, and operation and maintenancedescribed in this standard. Specifications shallbe recorded using approved specification sheets,job sheets, narrative statements in theconservation plan, or other acceptabledocumentation.

9 OPERATION AND MAINTENANCE An Operation and Maintenance Plan must beprepared for use by the landowner or operatorresponsible for PAM application. The plan shouldprovide specific instructions for PAM applicationsto insure it is used properly. Plan items mayconsist of: Reapply PAM to disturbed or tilled areas,including high traffic use areas. Monitoring advance phases of the irrigation toassure applications are discontinued whenrunoff begins. Equipment is operated and maintained toprovide uniform application rates. Maintenance of screens and filtering facilities. Rinse all PAM mixing and applicationequipment thoroughly with water to avoidformation of PAM residues. PAM is a flocculating agent that may causedeposition in downstream watercourses orother locations when it comes in contact withsediment-laden waters.

10 Downstreamdeposition from the use of PAM may requireperiodic cleaning to maintain normalfunctions.