Erosion & Sediment Control Technical Bulletin #2
APPLICATION OF ANIONIC POLYACRYLAMIDE FOR
SOIL STABILIZATION AND STORMWATER MANAGEMENT
Introduction
Anionic polyacrylamide (Anionic PAM) is a non-toxic chemical material that is being marketed nationwide for controlling
soil erosion and sedimentation on construction sites. Current independent research by state and federal institutions has
indicated that application of Anionic PAM in conjunction with conventional erosion and sediment controls (seed, mulch,
perimeter controls, sediment basins, etc.) can be a safe, effective, and economical (applied cost of ~$100-$300/acre)
technique for addressing problem soils on construction sites, when compared to conventional ESC measures alone. This
technical bulletin is not an official ESC State Standard & Specification or an endorsement of a specific Anionic PAM
product; specifications advocated for land-disturbing activities are listed in Chapter 3 of the Virginia Erosion & Sediment
Control Handbook. However, based on the recent number of inquiries regarding Anionic PAM and, most importantly,
it鈥檚 potential to prevent off site damage and aid compliance with the Virginia Erosion & Sediment Control Regulations, this
general guidance has been developed to assist land disturbers or plan-approving authorities that feel Anionic PAM may be
beneficial to a specific site. Following further use and testing in Virginia, DCR may consider including an Anionic PAM
specification in a future edition of the Handbook.
Background
鈥淧AM鈥? is a generic term for long-chain organic polymers that have been in use for many years as flocculating agents in
wastewater treatment and food processing plants; furrow agriculture; mining separations; petroleum recovery; and
personal care products. Extensive study has demonstrated that occupational exposure to Anionic PAM is NON-TOXIC
when used as directed and is not a Federally listed hazardous compound; however, Cationic PAM is highly toxic to
aquatic life and must NEVER be employed. Several states, NRCS, and EPA have recently completed guidance on the
use of Anionic PAM for sediment control on agricultural and construction sites. Anionic PAM products reduce erosion
and sedimentation by targeting the smallest soil particles, fine silts, clays and colloidal materials (5-10 microns in size),
which are difficult or impossible to control using conventional ESC measures. These smaller particles are commonly
maintained or introduced on site as fill because they are easily compacted. Silt fence and sediment basins, only trap
particles as small as 125 microns (sands and coarse silts) and >20 microns (silts), respectively. Thus, once liberated, the
smallest particles remain in the water column, and may necessitate complex and expensive solutions to prevent violations
and remediate property and environmental damage that may result if this material is transported off site in stormwater. In
a recent three-year efficacy study on construction sites, Anionic PAM provided up to 70% reduction in runoff-sediment,
and even better results when combined with conventional mulching and seeding measures.
Anionic PAM uses two mechanisms to affect these difficult to address particles. It preferentially increases aggregation of
these small particles to improve soil stability and prevent soil detachment in the first place, and decreases the settling time
of particles that become suspended to aid in their deposition within the site, thus improving runoff water quality.
Additionally, Anionic PAM can increases soil pore volume and permeability, thus increasing infiltration and reducing the
runoff quantity.
Anionic PAM is applied on site via two 鈥渄osing methods鈥? (direct, passive), and is available in four media types (powder,
powder dissolved in water [wet], emulsion, gel block). The powder, wet, and emulsion media are applied directly to short,
steep slopes, and other exposed soil surfaces for soil stabilization, while gel blocks are 鈥減assively鈥? used within a ditch or
conveyance system for in situ water treatment above pre-constructed sediment ponds. Further, to optimize performance,
preliminary site-specific assessment (soil and water testing) by a qualified manufacturer must be conducted to select
media, additives, dosing rate, dosing method, and maintenance procedure tailored to site-specific soil characteristics,
topography, hydrology, and type of erosion targeted.
Application of Anionic PAM to sites with problem soils in accordance with manufacturers guidance, this bulletin, and other
regulatory programs, shows great promise for improving compliance with NPS requirements, specifically Minimum
Anionic Polyacrylamide Guidance July 2002
1
Standards 1 (soil stabilization) and 19 (stormwater management) of the Virginia Erosion & Sediment Control Regulations
(4VAC50-30-40), and in turn, preventing degradation of off site property and water resources.
Applicability
Anionic PAM is intended for use on areas that contain high amounts of fine silt, clay, or colloidal soils. Anionic PAM
is generally applicable where the timely establishment of vegetation may not be feasible, is absent or inadequate, or where
topographic conditions, construction activities, or other forces limit the utility of conventional temporary sediment control
practices alone. Anionic PAM may be beneficial to the following activities/areas:
Staging areas
q
Rough grading operations
q
Balanced cut and fill earthwork
q
Man-made or natural stormwater conveyances
q
Haul roads
q
Roadside ditches
q
Soil stockpiles and borrow areas
q
After final grade and before paving, final seeding, and planting
q
Phased projects
q
Sites having a winter shut down
q
Other exposed areas that have not been adequately stabilized with vegetation or where other stabilization
q
measures would interfere with construction activities or are otherwise ineffective/inefficient for the area or time
of year.
As further discussed in the Application Restrictions section, the proper type of Anionic PAM must only be
applied in accordance with an approved plan/permit and on areas that ultimately drain to a pre-constructed
sediment trap or basin prior to introduction to surface waters.
Advantages & Limitations
Below is an inclusive list of common advantages and limitations that may apply to use of Anionic PAM. These issues
should be carefully considered before applying Anionic PAM to a specific site.
Advantages
q Improves stability of problem soils to prevent soil detachment in the first place
q Provides quick stabilization where vegetation has yet to be established
q Promotes flocculation (reduces settling time) of smallest particles
q Increases soil pore volume and permeability, thus decreasing imperious cover
q Less obtrusive than some conventional measures - doesn鈥檛 interfere with construction machinery/activity
q Convenient and easy to apply and store along with other soil amendments (fertilizer, mulch, etc.) with conventional
seeding, mulching, or irrigation equipment
q Material is specifically designed for the soil, waters, and other on site characteristics
q May prevent costly repair and reshaping of rilling or failing slopes
q Re-application may not be necessary for several months if treated areas are mulched
q Reduces seed, pesticide, and fertilizer (phosphorus and nitrogen) losses that hinder vegetation establishment on
site, increase costs, and promote nutrient and chemical loading offsite
q Non-toxic to aquatic biota
q Reduces windborne dust conditions
q May prevent water quality damages (TSS, turbidity), eutrophication, habitat destruction, stream channel erosion,
sedimentation, and related remediation costs
q Reduces potential for violations of MS-1 and MS-19
q Less expensive in the long-term by requiring less mulch, seed, etc. and corrective actions/remediation
Anionic Polyacrylamide Guidance July 2002
2
Disadvantages/Limitations
q Materials are 鈥渟oil-specific,鈥? so you can not reuse extra supply or bulk order for multiple sites
q Requires site-specific testing that may take several days to complete
q Energy intensive process (mechanical mixing) may be required for proper dissolution of viscous products
q May enhance precipitation of fine sediments in downstream structures, and therefore, increasing maintenance
requirements (removal of sediment/PAM complex from basins)
q Misuse (over use) by inexperienced parties that clog soils, thereby decreasing infiltration
q Are not effective when applied to pure sand or gravel with no fines, and when applied over snow cover
q Qualified manufacturers and distributors may not be currently available throughout the entire state
q Improper over-reliance on Anionic PAM, in lieu of proper conventional ESC measures
q May require engineers to consider Anionic PAM鈥檚 impact on existing seeding/fertilizer, pond sizing, and other
specifications
q Public concern over introduction of polymer products to the natural environment
Application Restrictions
To help ensure, safe, effective, and environmentally friendly application of Anionic PAM to construction sites, DCR has
established four site restrictions to Anionic PAM application. Note a qualified manufacturer should be consulted to
confirm a compliant and effective product is selected. It is suggested that applicants request references from
manufacturers and/or contact appropriate public agencies to confirm qualifications before contracting service.
ALL ANIONIC PAM APPLICATIONS MUST COMPLY WITH THESE RESTRICTIONS.
(1) Material
Only Anionic PAM and Anionic PAM mixtures that comply with the following criteria may be used. The criteria listed
below are generally included on the product label and/or Material Safety Data Sheet (MSDS).
PAM copolymer formulation must be anionic (negatively charged), with a charge density of 8 to 35% by weight
q
(15-18% is typical)
Ultra high molecular weight of 6 to 24 mg/mole (preferably 12-15 mg/mole)
q
Water-soluble, 鈥渓inear,鈥? or 鈥渘on-crosslinked鈥?
q
Highest grade Anionic PAM (potable drinking water grad 鈥? PDWG), certified for compliance with ANSI/NSF
q
Standard 60 and EPA and FDA residual acrylamide monomer (AMD) limits of 0.05% for drinking water/food
treatment
Non-combustible
q
Does not change soil pH
q
Expiration date included
q
Must be accompanied by MSDS and toxicity information from the manufacturer that the Anionic PAM product
q
and any required additives are non-toxic to aquatic biota (acute and chronic toxicity results using EPA protocols
approved under the Clean Water Act at 40 CFR 136) NOTE: Site-specific Anionic PAM product toxicity
or efficacy testing is not required by DCR at this time. However, compliance with other regulatory
programs/agencies may require this testing to ensure safe and compliant use on site.
Must be accompanied by manufacturers written instructions to ensure proper (1) Product and Site Preparation,
q
(2) Application, (3) Maintenance/re-application, (4) Storage, and (5) Safety, in accordance with Occupational
Health and Safety Administration (OSHA) and other applicable guidelines
NOTE: Cationic PAM (positively charged) shall never be used because of its toxicity to aquatic organisms at very
low concentrations. When used properly, Anionic PAM has no measurable toxicity to humans, aquatic organisms,
or plants. The high molecular weight Anionic PAM suggested herein present little concern for toxicity, as their
molecules are so ultra large that they do not penetrate biological membranes. Additionally when Anionic PAM is
introduced into waters containing sediments, humic acids, or other impurities, its effects are buffered to an even
greater degree. Further, acrylamide (a known carcinogen) residuals found in very small amounts in PAM products
is stringently regulated during manufacturing by EPA and FDA, so toxic concentrations do not reach the market.
Anionic Polyacrylamide Guidance July 2002
3
(2) Site-Specific Testing and Instructions
Users must obtain site-specific soil and water testing and guidance from a qualified manufacturer to ensure that an (a)
Anionic PAM product, (b) additives, and (c) application scheme are selected that is tailored to site-specific soil
characteristics (type, aggregate size, organic content, ion content), topography, hydrology, and type of erosion targeted.
Manufacturers generally provide this service at no cost. The final site-specific specifications, along with material
specifications noted in item 1 above, should be provided to the plan-approving authority to be included with the ESC plan.
(3) Application Conditions
Anionic PAM must always be applied above a pre-constructed sediment trap or basin inflow structure and never be
applied directly to:
q Slopes that flow directly into a wetland or state waters
q Sediment basins, traps, or other SWM ponds
q Wetlands or state waters
(4) Approvals and Permits
Anionic PAM use must conform to all federal, state, and local laws, rules, and regulations regarding use, discharge, and
disposal of chemical materials.
q Site-specific specifications for Anionic PAM must always be consistent with this bulletin, included with the ESC
plan, integrated with other conventional measures to maximize effectiveness, and approved by the appropriate
plan-approving authority 鈥? Anionic PAM should not be used IN LIEU of conventional measures!
q Users must contact the appropriate local, regional, and/or state authority to confirm that Anionic PAM use will not
conflict with any site-specific Virginia Discharge Elimination System Permits (VPDES), Virginia Water Protection
Permits, or other discharge or wetlands permits
Application Considerations
As noted in the Materials subsection above, the manufacturer is required to provide written application instructions for
Anionic PAM. The following are additional considerations and recommendations relating to the use of Anionic PAM that
may enhance effectiveness or avoid problems.
EXCEPT FOR THE APPLICATION RESTRICTIONS IN THE PREVIOUS SECTION, MANUFACTURERS
APPLICATION GUIDELINES MUST ALWAYS BE FOLLOWED AND TAKE PRECEDENCE OVER THESE
ADDITIONAL CONSIDERATIONS.
General Considerations
DO NOT OVER APPLY ANIONIC PAM. Excessive application of Anionic PAM can lower infiltration rates
q
or increase suspended solids in water. Note that application rates of Anionic PAM above those
suggested by the manufacturer will not provide additional effectiveness. More is not better!
Published literature and guidance recommends that application of Anionic PAM in pure form (75%-90% active
q
polymer) not exceed 10 lbs/acre per single application event, 200 lbs/batch, or 200 lbs/acre/year.
Note that for Anionic PAM to work effectively there must be a source of 鈥渄ivalent cations.鈥? Gypsum (CaCl2) is a
q
common source. The divalent cation source may be in the Anionic PAM mix, in the soil, or applied directly to the
soil. Manufacturers soil tests should be used to determine whether additives are necessary.
Care must be taken to prevent spills onto paved surfaces, as Anionic PAM may be very slippery. Skid protection
q
should be employed in wet areas.
Gloves should be worn whenever handling Anionic PAM and surfaces that contacted them.
q
Consider all OSHA health and safety precautions and manufacturers instructions.
q
Anionic Polyacrylamide Guidance July 2002
4
Direct Application Considerations
q Recent publications suggest that Anionic PAM application costs will range from $107 - $222/acre
q Do not add water to powdered Anionic PAM. Add Anionic PAM powder slowly to water to the desired
concentration and mix for 3 to 5 minutes. If water is added to PAM, globs may form that can clog dispensers 鈥?
this indicates incomplete dissolving of the Anionic PAM, and therefore, increases the risk of under-application.
q Including tackifers, mulch, seed, and fertilizer in the final Anionic PAM mixture is recommended to improve
performance and provide additional permanent protection beyond the useful life of the Anionic PAM. However,
Anionic PAM should always be the final additive to the mixture.
The Anionic PAM mixture should be prepared immediately prior to application as effectiveness decreases if too
q
much time passes between mixing and application.
q Application to dry soil is preferred.
q May be sprayed on bare soil using standard irrigation equipment, hydroseeding,/hydromulching equipment, water
trucks, or other spraying devices that have a mechanical agitator, mixing apparatus, or hydrologic recirculation.
q Marking with tracer or colorant to visually track application is recommended.
q Use a minimum 30 ft. setback when applying near wetlands or surface waters.
q Procedures for application should ensure uniform coverage to the target area and avoid drift to non-target areas.
q Inhaling powdered Anionic PAM in large quantities may cause choking or difficulty breathing. Persons handling
and mixing Anionic PAM should use a dust mask of a type recommended by the manufacturer.
q If Anionic PAM powder gets on skin or clothing, wipe off with a towel rather than washing with water.
q Limit exposure of the powder Anionic PAM supply, as air and sunlight degrade effectiveness in 3 months.
Passive Application Considerations
q Gel block media size and shape should be regulated to deliver the appropriate dosage within a particular
conveyance 鈥? applicants should work with the manufacturer to ensure sediment removal.
q Gel blocks should generally be placed in the center of the ditch as close as possible to the active land-disturbing
activities and an appropriate distance above the inflow of the sediment trap or basin to ensure adequate turbulence
and mixing energy for flocculation in the downstream sediment trap or basin.
q Stakes, nylon mesh bags, wire cages, and other equipment used to maintain/protect the block within the
conveyance should be installed in accordance with manufacturers directions.
Maintenance and Disposal
Degradation of PAMs in soil systems can be expected to occur as a result of mechanical degradation, chemical and
biological hydrolysis, sunlight, salt, and temperature effects at a rate that has been estimated to be approximately 10% per
year. However, these effects are accelerated in highly exposed areas. Anionic PAM may be reapplied in accordance
with manufacturers instructions to disturbed areas after a 48-hour period. Reapplication is not required unless Anionic
PAM treated soil is disturbed or turbidity or water quality show the need for an additional application. If PAM treated soil
is left undisturbed, a reapplication may be necessary after 6-8 weeks. Further Anionic PAM applications may be required
for steep slopes, highly silty and clayey soils, long grades, and high traffic or precipitation areas. Note that if Anionic
PAM is first applied to bare soil and then covered with mulch, a reapplication may not be necessary for several
months. Continue to monitor areas to which Anionic PAM has been introduced after every precipitation event and until
treated areas are permanently stabilized.
All equipment should be maintained to provide the application rates recommended by the manufacturer. Rinse all
equipment used to mix and apply Anionic PAM thoroughly with water to avoid formation of residues.
Anionic PAM may enhance precipitation of fine sediments in downstream pipes, channels, and detention basins.
Accordingly, these structures should be inspected periodically and sediment removed when it exceeds 10% of the
structure鈥檚 mean depth or in accordance with the clean out schedule recommended for the particular measure.
Anionic Polyacrylamide Guidance July 2002
5
Recovered sediments containing Anionic PAM should be reused or disposed of in accordance with local, state, and Federal
regulations. Anionic PAM is not listed in Federal hazardous waste regulations (Comprehensive Environmental Response,
Compensation, and Liability Act of 1980, Public Law 96-510, as amended by the Superfund Amendments and
Reauthorization Act of 1986, Public Law 99-499), or in the Virginia Hazardous Waste Management Regulations
(9VAC20-60-12 et seq.). Accordingly, recovered sediments may be dewatered appropriately and used as a fill material, or
alternatively, may be land applied if the sediment does not have the structural stability to act as fill.
Further Information
Requests for further information or questions regarding the application of Anionic PAM to construction sites in Virginia
should be directed to qualified manufacturers or DCR鈥檚 Central Office in Richmond, VA.
References
AGC of Washington Education Foundation. 2000. Experimental BMP 5.0-PAM. Construction Site Erosion and
Sediment Control Certification Course Manual. Sections 4.1.1 鈥? 4.1.5.
Applied Polymer Systems, Inc. (APS). 2000. Promotional materials and Material Safety Datasheets regarding Silt Stop
(APS 630, 640, 705, 730, and 740) and Floc Log (APS 702, 703, 730, and 732) PAM products.
Georgia Soil and Water Conservation Commission. 2000. Polyarylamide (PAM). Manual for Erosion and Sediment
Control in Georgia, 5th Edition. pp. 6-67 鈥? 6-68.
Green, S.E. and D.E. Stott. 2001. Polyacrylamide: A Review of the Use, Effectiveness, and Cost of a Soil Erosion
Control Amendment. Pp. 384-389. In: Sustaining the Global Farm. Selected Papers from the 10th International
Soil Conservation Organization Meeting held May 24-29, 1999, Purdue Univerity and the USDA-ARS National
Soil Erosion Research Laboratory.
Lentz, R.D., T.D> Stieber, and R.E. Sojka. 2000. Applying Polyacrylamide (PAM) to Reduce Erosion and Increase
Infiltration Under Furrow Irrigation. U.S. Department of Agriculture, Agricultural Research Service,
Northwest Irrgation and Soils Research Lab. Adapted from: Lentz, R.D., T.D. Stieber, and R.E. Sojka. 1995.
Applying polyacrylamide (PAM) to reduce erosion and increase infiltration under furrow irrigation. p. 79-
92. In L.D. Robertson, P. Nolte, B. Vodraska, B. King, T. Tindall, R. Romanko, J. Gallian (ed.) Proc. Winter
Commodity Schools - 1995. University of Idaho Cooperative Extension, Moscow, Idaho. Posted on USDA-ARS
website.
Michigan Department of Environmental Quality, Surface Water Protection Division. Undated. Technical Guidance for
the Use of Polyacrylamides for Soil Erosion Control.
Mostaghimi, K.A., K.A. Flahive, P.W. McClellan, A. Mendez, and D.H. Vaughn. 2000. A Comparative Investigation
of the Effectiveness of Polyacrylamide (PAM) for Erosion Control in Urban Areas. Biological Systems
Engineering Department, Virginia Tech, Blacksburg, VA. Unpublished report prepared for Virginia Department of
Conservation and Recreation. (Includes extensive summary of current literature regarding PAM)
Natural Resource Conservation Service. 2001 Anionic Polyacrylamide (PAM) Erosion Control. Code 450. pp. 450-1
鈥? 450-3.
Oregon Department of Environmental Quality. 2000. Best Management Practices for Storm Water Discharges
Associated with Construction Activities, BMP #30 鈥? Flocculants and Coagulants. Construction BMPs
Manual, Volume II. pp. 40 鈥? 46.
Anionic Polyacrylamide Guidance July 2002
6
Roa-Espinoza, A., G.D. Bubenzer, and E.S. Miyashita. 2000. Sediment and Runoff Control on Construction Sites
Using Four Application Methods of Polyacrylamide Mix. Proceedings of the National Conference on Tools
for Urban Water Resource Management and Protection. USEPA Office of Research and Development.
EPA/625/R-00/001. pp. 278-283
Roa, A. 1997. Are there Safety Concerns or Environmental Concerns with PAM? Dane County Land Conservation
Department.
Sojka, R.E.. 2001. Potential Use of Polyacrylamide (PAM) in Australian Agriculture to Improve Off- and On-site
Environmental Impacts and Infiltration Management. Report to the Australian Land and Water Resource
Research Development Council, the Institute for Sustainable Irrigated Agriculture, Goulburn-Murray Water, and
USDA Agricultural Research Service. Posted on USDA-ARS website.
Sojka, R.E., D.L. Lentz, and D.L. Bjorneberg. 2001. Aase, J.K. The PAMphlet: A concise guide for safe and
practical use of polyacrylamide (PAM) for irrigation-induced erosion control and infiltration
enhancement. U.S. Department of Agriculture, Agricultural Research Service, Northwest Irrgation and Soils
Research Lab. Posted on USDA-ARS website.
Sojka, R.E., and R.D. Lentz. 1996. A PAM Primer: A brief history of PAM and PAM related issues. U.S.
Department of Agriculture, Agricultural Research Service, Northwest Irrgation and Soils Research Lab. Posted
on USDA-ARS website.
Tobiason, E., K. Jenkins, E. Molash, E., and S. Rush. 2001. Polymer Use and Testing for Erosion and Sediment
Control of Construction Sites. Erosion Control. January/February 2001. pp. 90-101.
U.S. Environmental Protection Agency. 2002. Construction Site Storm Water Runoff Control 鈥? Chemical
Stabilization. Stormwater Phase II Menu of BMPs & Model Permits. EPA Office of Wastewater Management
webpage.
U.S. Environmental Protection Agency. 1994. Chemical Summary for Acrylamide. Office of Pollution Prevention and
Toxics. EPA-749-F-94-005a.
Virginia Administrative Code. 4VAC50-30. Virginia Erosion & Sediment Control Regulations.
Virginia Department of Conservation & Recreation. 1992. Virginia Erosion & Sediment Control Handbook.
Chapter 3: State Minimum Standards & Specifications. Third Edition.
Washington Department of Ecology. 2000. BMP C126: Polyacrylamide for Soil Erosion Protection. Final Draft of
Stormwater Manual for Western Washington, Volume II 鈥? Construction Stormwater Pollution Prevention. pp. 84-
88.
Washington Department of Transportation. Undated. WSDOT Draft Experimental BMP 鈥? Quality Assurance / Quality
Control Plan: Polyacrylamide For Soil Erosion Control and Flocculation of Stormwater Detention Ponds
at Highway Construction Sites. WSDOT Highway Runoff Manual, Section 4.4. WAC173-270-030.6.a. pp. 1-
28.
Washington Department of Transportation. 1997. WSDOT Stormwater Management Plan. Volume 5.3. pp. 45-51.
Wisconsin Department of Natural Resources. 2001. Erosion Control 鈥? Land Application of Anionic Polyacrylamide.
Code 1050.
Anionic Polyacrylamide Guidance July 2002
7
|