for the Use of
Polyacrylamides (PAM) and PAM Blends for
Soil Erosion Control and Storm Water clarification
PAM is a water-soluble anionic polyacrylamide
product used to minimize soil erosion caused by water and wind to
decrease soil sealing by binding soil particles, especially clays,
to hold them on site. In addition, these types of materials may
also be used as a water treatment additive to remove suspended
particles from runoff. When PAM is used on construction sites in
the Southeast it is typically applied with temporary seeding and
or mulching on areas where the timely establishment of temporary
erosion control is so critical that seedings and mulching need
additional reinforcement. It may be used alone on sites where no
disturbances will occur until site work is continued and channel
erosion is not a significant potential problem. Permanent grassing
applications can be better established using PAM as a tackifier
and soil conditioner.
PAMs are manufactured in various forms to be used
on specific soil types, and are applied at a rate of up to 50 pounds/acre for dry products and 2 ½ gallons/acre of
emulsion-liquid products. Using the wrong form of a PAM on a soil
will result in some degree of performance failure, and increase
the potential for this material to enter surface waters. PAM used
alone may not reduce NTU values resulting in noncompliance water
quality discharges or poor soil binding conditions. Site-specific
soil-PAM testing must be performed. Exceeding the maximum
application rates for this product does not increase the
effectiveness of the product. Block or Log forms of PAM and PAM
blends are manufactured for specific use in drainage waterways to
remove suspended particulates from runoff.
General Components of the Practice
Prior to the start of construction, a qualified professional
should design the application of PAM and plans and specifications
should be available to field personnel.
The application should conform to the design and
specifications provided in the plans. Typical applications include
the following components.
- Site Preparation
- Equipment Preparation
- PAM Application
Prepare site following design and specifications.
If using a liquid application system, pump a surfactant through
the injection system before and after injecting concentrated
liquid PAM into sprinkler irrigation systems to help prevent
valves and tubing from clogging.
PAM used in hydroseeding applications should be
added as the last additive to the mix.
After their use, rinse all PAM mixing and
application equipment thoroughly with water to avoid formation of
PAM residues. Rinse residue should be applied to soil areas to
create binding to the soil structure and increase erosion
PAM Application- Criteria for Land applied PAM Specifications
PAM shall be mixed and/or applied in accordance with
all Occupational Safety and Health Administration (OSHA) Material
Safety Data Sheet (MSDS) requirements and the manufacturer’s
recommendations for the specified use conforming to all federal,
state and local laws, rules and regulations.
All venders and suppliers of PAM, PAM mix or blends shall present
or supply a written toxicity report which verifies that the PAM,
PAM mix or blend exhibits acceptable toxicity parameters which
meet or exceed the EPA requirements for the state and federal
water quality standards. Whole effluent testing does not meet this
requirement as primary reactions have occurred and toxic
potentials have been reduced.
Cationic forms of PAM, polymers and
chitosan are not allowed for use under this guideline due to their
high levels of toxicity to aquatic organisms. Emulsions shall
never be applied directly to stormwater runoff or riparian waters
due to surfactant toxicity.
All venders and suppliers of PAM, PAM mix or blends shall supply
written “site specific” testing results demonstrating that a
performance of 95% or greater reduction of NTU or TSS from
Emulsion batches shall be mixed following
recommendations of a testing laboratory that determines the proper
product and rate to meet site requirements. Application method
shall insure uniform coverage to the target area. (Emulsions
shall never be applied directly to stormwater runoff or riparian
Dry form (powder) may be applied by hand spreader
or a mechanical spreader. Mixing with dry silica sand will aid in
spreading. Pre-mixing of dry form PAM into fertilizer, seed or
other soil amendments is allowed when specified in the design
plan. Application method shall insure uniform coverage to the
Block or Log forms shall be applied following site
testing results to assure proper placement and performance and
shall meet or exceed state and federal water quality requirements.
Consult with a registered design professional for
assistance if any of the following occur:
- Problems with application equipment clogging.
- PAM alone may not meet testing requirements for NTU reduction
and soil stabilization. Site specific “blends” may be needed to
meet these requirements.
- Application specifications for PAM cannot be met; alternatives
may be required. Unapproved application techniques could lead to
- Visible erosion occurs after application.
An operation and maintenance plan must be prepared
for use by the operator responsible for PAM application. Plan
items should include the following items.
- Reapply PAM to disturbed or tilled areas that
require continued erosion control.
- Maintain equipment to provide uniform application rates.
- Rinse all PAM mixing and application equipment thoroughly with
water to avoid formation of PAM residues and discharge rinse water
to soil areas where PAM stabilization may be helpful.
- Downstream deposition from the use of PAM may require periodic
sediment removal to maintain normal functions.