Temporary ditch sumps are not effective perimeter controls. Other sediment control practices shall be utilized prior to channels discharging into public waterways.
VI. Considerations
A. Directional tracking may compact the soil, therefore additional seedbed preparation may be required. Refer to WDNR Conservation Practice Standard Seeding for Construction Site Erosion Control (1059) for seedbed preparation and seeding criteria.
B. When constructing a temporary ditch sump, compacting the dike provides additional stability.
C. Consider at a minimum excavating ½ cubic yard per 1% gradient, for every 500 feet of channel when constructing temporary ditch sumps.
VII. Plans and Specifications
Due to the interim nature of these practices, and the fact that location determinations are made in the field, they need only be referenced in the erosion control plan narration or general notes.
VIII. Operation and Maintenance
These practices shall be inspected and repaired or reinstalled after every runoff event.
IX. References
Virginia Department of Conservation and Recreation. 1992. Virginia Erosion and Sediment Control Handbook, Third Edition. Chapter
3 – 3.29 Surface Roughening.
Dane County. 2002. Dane County Erosion Control and Stormwater Manual, First Edition. Appendix Surface Roughening S-16.1.
X. Definitions
Temporary (I): An erosion control measure that is utilized during construction site grading activities.
Interim Sediment Control
Water Application of Polymers
1051 (11/02)
Wisconsin Department of Natural Resources
Conservation Practice Standard
Note: Words in the standard that are shown in italics are described in IX. Definitions. The words are italicized the first time they are used.
l. Definition
The application of products containing polymers1 to sediment control structures.
ll. Purpose
The purpose of this practice is to settle out or remove suspended
sediment from water within sediment control structures.
lll. Conditions Where Practice Applies
This practice shall be used with self-contained sediment control structures, on a temporary basis for construction sites, in an emergency for post-construction sites and only continually at sites holding an individual permit, if needed to improve the sediment removal efficiency of the structure. Polymers shall not be directly applied to surface waters of the state. Sediment control structures may be within, or discharge to, surface waters of the state.
lV. Federal, State and Local Laws
Water applications of polymer shall comply with all federal, state, and local laws, rules or regulations governing polymers. The operator is responsible for securing required permits. This standard does not contain the text of the federal, state, or local laws governing polymers.
V. Criteria
A. Toxicity Criteria
If used in accordance with the use restriction, the polymer mixture shall meet an acceptable level of risk such that the product can be used without significant harm to organisms that inhabit or come in contact with the aquatic environment. Every attempt shall be made to eliminate the use of any chemicals known to be environmentally toxic within a polymer mixture. Polymer mixtures shall be non-combustible.
The manufacturer shall supply toxicity testing data to the Wisconsin Department of Natural Resources (WDNR) based on the polymer mixture, including any binding or buffering agents, catalyst or any other additives.
1. The use of cationic polyacrylamide shall be avoided where there is danger of impacting aquatic organisms because its toxicity to aquatic test species occurs at very low concentrations.
2. Anionic polymer mixtures shall have ≤ .05% free acrylamide monomer by weight as established by the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA).
3.
Each manufacturer shall provide to the WDNR toxicity information (including acute and chronic water column toxicity test data) from a certified lab, as defined in ch.
NR 149 Wis.Adm.Code, for the polymer mixture.
This data shall include all raw and statistical data regarding death, sub-lethal observations such as immobility, and any other test observations. Standardized toxicity testing procedures should be used and referenced. A use restriction will be calculated by WDNR using the information in Appendix I.
4. Users of polymer mixtures shall obtain and follow all Material Safety Data Sheet (MSDS) requirements, manufacturer's recommendations, and WDNR use restrictions.
B. Application Criteria
1. Maximum application rates, per storm event, in pounds per acre-feet shall be the lesser of WDNR's use restriction multiplied by 1.35 or the manufacturer's recommended application rate (1.35 is a conversion factor that is used to change the use restriction from ppm to an application rate in pounds per acre-feet).
2. Neither the manufacturer's written application rate recommendations, nor the application rate shall exceed the WDNR use restriction. The manufacturer or distributor shall provide for the applicator:
a. Labels affixed to the polymer mixture containers that indicate the recommended application rate and the maximum application rate based on the use restriction.
b. A product expiration date for the polymer mixture based on product expiration dates of the polymer.
c. General written application methods.
d. Written instructions to provide proper safety, storage, and mixing of their product.
3. The application method shall provide for uniform distribution of the product in the sediment control structure and shall consist of either:
a. Passive Applications: Polymers applied by non-mechanically dosing the sediment-laden inflow prior to it entering the impoundment area of the sediment control structure. The manufacturer shall base passive application rates on the dissolution rate and/or the dead storage volume of the sediment control structure.
or
b. Active or Mechanical Applications: Polymer applied by mechanically or hydraulically mixing directly into a sediment control structure.
4. The applicator of the polymer mixture shall at the time of application, document the following:
• Name of applicator
• Application rate in pounds per acre-feet of stormwater runoff
• Date applied
• Product type
• Weather conditions during application
• Method of application
Copies of this documentation shall be entered into the contractor's monitoring log or a project diary and made available upon request.
C. Product Approval Criteria
The manufacturer shall certify, through independent sampling and test results, that their product performs as per the following requirements. (The product approval process is depicted in flow chart form in Figure 1.)
1. The toxicity information required in section V.A.3. of this standard shall be reviewed by the WDNR and used to generate a written product use restriction for the polymer mixture. Appendix I outlines the information that needs to be submitted as a part of this review, and states where they must be submitted.
2. Polymer mixtures shall achieve = 95% sediment reduction as measured by the standpipe method outlined in Appendix II.
3. Performance criteria - active and passive applications shall be field tested and submitted separately:
a. The performance of polymer mixtures shall be verified and field-tested in a body of water that is not discharging directly into the waters of the state. The body of water shall be a minimum of 1/3-acre surface area and an average depth of at least 3 feet.
b. The total suspended solids prior to the polymer treatment must be tested and verified by an independent testing lab, and must have a minimum value of 800 ppm or equivalent Nephelometric Turbidity Units (NTU) and be visibly turbid. The relationship between total suspended solids (TSS) and NTU is site-specific and the derivation of a unique TSS-NTU relationship shall be conducted for each sediment control structure. A minimum of two samples per acre-foot of water shall be taken from random locations within the test site.
c. Within 48 hours from the initial treatment of the water body, the total suspended solids must have a maximum of 80 ppm, or equivalent NTU.
d. Testing sites may not be used for subsequent testing for a period of 3 months from the time of initial application.
e. The Wisconsin Department of Transportation (WisDOT) shall be notified at least 7 days prior to testing, and WisDOT and/or WDNR staff shall be allowed to monitor any such testing.
4. The WisDOT Erosion Control Storm Water/Product Acceptability List Committee will review and approve products as per the process set forth in WisDOT's Product Acceptability List (PAL).
5. The polymer mixture must be resubmitted if any portion of the mixture is altered subsequent to its approval. Such alterations may include:
a. The amendment of base polymers and/or any other additives
b. The ratios of individual components
VI. Considerations
The following are additional recommendations, which may enhance the use of, or avoid problems with, the practice.
A When using products in impoundments immediately adjacent to, or within waters of the state, consider using products for which the manufacturer's recommended application rate is considerably lower than the use restriction.
B. The applicator should use the least amount of polymer mixture to achieve optimal performance.
C. Polymer mixtures should be applied in conjunction with other erosion control BMPs and under an erosion and sediment control or stormwater management plan.
D. Test the pH of the water in the sediment control structure and follow the manufacturer's recommended pH range for their polymer mixture, as pH will impact the effectiveness of polymer mixtures.
E. Ethylene glycol, propylene glycol or any other known environmental toxicants should not be included in the polymer mixture.
F. Care must be taken to prevent spills of polymer mixtures. Follow the manufacturer's recommended cleanup procedures in the event of a spill.
G. Inhaling granular polymer may cause choking or difficulty breathing. Persons handling and mixing polymer should use personal protective equipment of a type recommended by the manufacturer.
H. Polymer mixtures combined with water are very slippery and can pose a safety hazard.
I. Polymer mixtures should be considered as an aid to removing solids from dredge slurries.
J. Where polymer mixtures are used with sediment control structures in the stream, such as during bridge construction, the structure should not be removed until the water is clarified. If the resulting sediment floc is more than a half a foot deep it should be excavated or filtered out.
VII. Specifications
Erosion and sediment control and stormwater management plans specifying polymer mixtures for sediment control shall be in keeping with this standard and shall describe the requirements for applying the practice to achieve its intended purpose.
VIII. Operation and Maintenance
Sediment levels on the bottom of the sediment control structure shall be monitored to measure the loss of storage capacity over time due to enhanced sedimentation by the polymer mixture.
IX. Definitions
Material Safety Data Sheets (MSDS) (V.A.3) Provide basic information on a material or chemical product intended to help someone work safely with the material. This includes a brief synopsis of the hazards associated with using a material, how to use it safely, and what to do if there is an emergency. The retail distributor and/or manufacturer as per OSHA's Hazard Communication Standard,
29 CFR 1910.1200, must provide MSDS, with the purchase of potentially hazardous products.
Nephelometric Turbidity Units (NTU) (V.C.3.b) A measure of the amount of light scattered by suspended and dissolved materials in the sample.
