Using Water Effect Ratio In Setting NPDES Permit Limits

The water effect ratio (WER) is defined as the ratio of the toxicity of a chemical in site water to the toxicity of the same chemical in standard laboratory water. Standard laboratory water would have been used to generate toxicity data used to calculate State or Federal Water Quality Criterion. Therefore a WER which is greater than or less than 1 would infer that the chemical would be more or less toxic in site water compared to laboratory water. Using the Water Effect Ratio, the ambient water quality standard might be adjusted to meet the same aquatic life protection goals. The water effect ratio is developed to compensate for site-specific biogeochemical factors such as hardness, alkalinity, organic carbon, etc. which can influence the bioavailability and toxicity of chemical.

In practice, WER are often used to generate site-specific water quality standards that are higher than State or Federal standards.

The process of generating and using WER in the NPDES permitting process requires close coordination with the permitting agency. Work to prepare acceptable WER may require water quality monitoring and laboratory toxicity tests. NPDES permits issued using a WER may also include additional receiving water monitoring requirements.


Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

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Iowa IDNR General Permit for Well Construction Wastewater Discharges

The Iowa Department of Natural Resources (DNR) is proposed amendments to Chapter 64 – Wastewater Construction and Operation Permits, including a proposal that would require the discharge of wastewater from water well construction and service activities to navigable waters to be covered under a general permit. The proposal would create a National Pollutant Discharge Elimination System (NPDES) General Permit that would require permittees to:

1. Comply with the general water quality criteria,

2. Prepare a pollution prevention plan that includes best management practices (BMPs) to be implemented, and

3. Visually monitor wastewater effluent to determine sufficiency of the BMPs.

The IDNR will be conducting public hearings on the proposed rules at several locations from August 4 through 12.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

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Court Approves MPCA Vessel Discharge Permit Rules

The Minnesota Court of Appeals ruled in favor of the Minnesota Pollution Control Agency’s (PCA) new regulations to control ballast water discharges from ships on Lake Superior.

The Minnesota Center for Environmental Advocacy had filed suit against the PCA saying the agency was moving too slowly and had standards too lax to regulate ballast water. The group wanted tougher standards on ships imposed sooner than 2012 for new ships and 2016 for existing ships the PCA has called for.

The court’s decision upholds the rules promulgated by the PCA last year for nearly all ships that discharge any ballast water or carry ballast water through Minnesota waters of Lake Superior.

[Read more about Vessel Discharge Permits]

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

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Mercury TMDL - MPCA Proposal To Control Hg Air Emissions

The Minnesota Pollution Control Agency (MPCA) is requesting comments on new air quality rules involving mercury air emissions reporting. The Rules are being drafted in accordance with a statewide mercury TMDL, which aims to reduce mercury in fish.

The impeding rulemaking falls into two general categories:

1) Mercury Emissions Reporting, and
2) Plans for Mercury Emissions Reductions at Certain Facilities

Rulemaking will require certain facilities holding an MPCA air emissions permit to develop their own Mercury Emissions Reducing Plan for incorporation into their State air emissions permit. Some facilities will also be expected to develop reduction plans to meet sector or source reduction targets and timeframes listed in the “Strategy Framework for the Implementation of Minnesota’s Statewide TMDL”, which outlines the State's strategy to address the many lakes & rivers in the State impaired due to high concentrations of mercury in fish.

The proposed new and amended rules will also establish the emission calculation methods for facilities to track their mercury emissions and submit an annual mercury emissions report to the MPCA. Although MPCA is considering having mercury emissions reporting take place concurrent with the annual air emissions inventory process, the proposed rulemaking does not include any major changes to the criteria pollutant emissions inventory.

The proposed rule will also establish the minimum requirements for Mercury Emissions Reduction Plans from each facility to address how they will reduce mercury emissions. The Plans will either be incorporated into their air emissions permit as enforceable requirements or will be made enforceable using other means available to the MPCA. Reduction targets are established for taconite processing facilities, utility boilers, commercial, institutional and industrial boilers, petroleum refineries, secondary metal smelters, sewage sludge incinerators.

As a separate element of the Statewide TMDL, MPCA is also proposing evaluations for mercury sources as a requirement under its Multi-sector Industrial Stormwater General permit. Facilities that identify mercury sources will need to develop a Mercury Minimization Plan relative to stormwater discharges.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

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Iowa Chloride, Sulfate and TDS Ambient Water Quality Standards

The Iowa Department of Natural Resources (IDNR) is currently proposing to amend Iowa ambient water quality standards for chloride, sulphate and total dissolved solids (TDS). In addition, they are proposing a change to the default hardness value used to calculate ambient water quality standards for many chemicals, especially metals.

The changes being proposed include the following:

• Establish numerical water quality criteria for chloride for the protection of aquatic life uses.
• Establish numerical water quality criteria for sulfate for the protection of aquatic life uses.
• Remove TDS criteria and implementation approach
• Revises default hardness level used for hardness dependent chemical criteria from 100 mg/l (as CaCO3) to 200 mg/L.

IDNR will be accepting comments on these proposed changes until August 14, 2009.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

Caltha LLP Aquatic Toxicology / WQ Standards Services Website

Draft Clean Water Restoration Act Approved By Senate Committee

The US Senate Senate Environment and Public Works Committee has approved a bill, "the Clean Water Restoration Act", that will clarify the scope of the Federal Water Pollution Control Act Amendments of 1972 ("Clean Water Act") definition of "waters of the United States". Under the draft bill, waters of the US would be defined as including:

(A) all waters which are subject to the ebb and flow of the tide;
(B) all interstate waters, including interstate wetlands;
(C) all other waters, such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds;
(D) all impoundments of waters of the United States;
(E) tributaries of the aforementioned waters;
(F) the territorial seas; and
(G) wetlands adjacent to the aforementioned waters;

The draft bill specifically excludes groundwaters from the definition of waters subject to the Clean Water Act. As always, States can decide to include additional types of waters to be included as "waters of the State". Some States already include groundwater under this definition.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

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Great Lakes Initiative GLI Human Health Based Criteria

What is a Human Health-based Water Quality Criterion?

The Water Quality Guidance for the Great Lakes System, also known as the Great Lake Initiative or GLI (40 CFR 132), created a few new types of water quality standards intended to be applied to waters in the Great Lakes basin.

A Great Lakes Water Quality Human Health-based Criterion (HHC) is intended to protect humans from unacceptable exposure to toxicants via consumption of contaminated fish and drinking water and from ingesting water as a result of participation in water-oriented recreational activities. The criteria were developed to provide a level of protection likely to be "without appreciable risk" of carcinogenic and/or noncarcinogenic effects.

Chemical concentration levels protective of human health are derived based on either a Tier I (“Tier I Criterion”) or Tier II (“Tier II Value”) classification. The two Tiers are primarily distinguished by the amount of toxicity data available for deriving the concentration levels and the quantity and quality of data on bioaccumulation.

For known or suspected carcinogenic chemicals, the criterion are derived at a level corresponding to an incremental cancer risk of 1 in 100,000. Noncarcinogens are generally assumed to have a threshold dose or concentration below which no adverse effects should be observed. The Tier I criterion or Tier II value is the maximum water concentration of a substance at or below which a lifetime exposure from drinking the water, consuming fish caught in the water, and ingesting water as a result of participating in water-related recreation activities is likely to be without appreciable adverse effects.

Human-health based water quality criteria were derived for 17 compounds (see below); however, the GLI detailed the methodology to derive human health-based criteria for other compounds.

Benzene
Chlordane
Chlorobenzene
Cyanides
DDT
Dieldrin
2,4-Dimethylphenol
2,4-Dinitrophenol
Hexachlorobenzene
Hexachloroethane
Lindane
Mercury/methylmercury
Methylene chloride
2,3,7,8-TCDD
Toluene
Toxaphene
Trichloroethylene

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

Caltha LLP Aquatic Toxicology / WQ Standards Services Website