Water Quality Standards | Aquatic Toxicology

Wednesday, March 4, 2009

Water Quality Standards on Mississippi - EPA Requirements for MDNR

In December 2008, US EPA informed the Missouri Department Natural Resources (MDNR) that new or revised water quality standards are necessary to protect portions of the Mississippi River in Missouri.

MDNR designated many stream segments and all of its lakes for recreational uses. However, Missouri did not assign the highest level of recreational use to a 195.5-mile segment of the Mississippi River that flows from St. Louis to the confluence of the Mississippi and Ohio Rivers. This EPA action directs the State to address approximately 160 miles of the Mississippi River to ensure that swimming, water-skiing and other recreational uses are protected. This will require MDNR to assign more stringent water quality criteria, which may in turn result in tighter wastewater discharge permit limits.

This action could impact many municipal and industrial NPDES permitted discharges in this reach of the Mississippi River, whether or not existing water quality data indicate that the river does/ does not currently meet recreational use standards.

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

Tuesday, March 3, 2009

Proposed Antidegradation Policy - Extension of DNR Comment Period

The Iowa Department of Natural Resources (DNR) has extended the public comment period on the proposed antidegradation rules to March 4.

Antidegradation policy is one of the three components of Iowa water quality standards - 1) designated uses, 2) water quality criteria to protect those uses, and 3) antidegradation policy. The Iowa DNR is proposing a four-tiered approach, including creating a guidance document that establishes procedures for implementing the antidegradation policy.

The changes being proposed include the following:

Incorporate by reference the document entitled “Iowa Antidegradation Implementation Procedure,” which proposes an approach to be followed in assessing and minimizing degradation of Iowa’s surface waters

Update antidegradation policy language with four tier approach, and

Remove High Quality (Class HQ) and High Quality Resource (Class HQR) designated uses and add several waters to the newly proposed Outstanding Iowa Water (OIW) category.

MPCA Water Quality Standards - Revised Rule 7050 - 7052

The Minnesota Pollution Control Agency (MPCA) is requesting comments on its planned amendments (“Triennial Review”) to rules governing state water quality standards found in Minnesota Rules Chapters. 7050 and 7052.

- Chapter 7050 includes provisions to protect Minnesota’s waters from pollution.
- Chapter 7052 provides standards specific to surface waters of the state in the Lake Superior Basin.

The Federal Clean Water Act (CWA) requires States to review their water quality standards every three years (“Triennial Review”) and to amend and update them if necessary. The MPCA initiated this triennial review by seeking comments in a Request for Comments published in the July 28, 2008, State Register. The key amendments being considered for the upcoming Triennial Review include:

Planned Amendments for Numeric Standards for Class 2 waters
Eutrophication standards for river systems.
Revised turbidity standards
New or revised contaminant standards for protection of aquatic life and human health from toxic effects related to:
1. Cadmium
2. Copper
3. Chloride
4. Diazinon
5. Nonylphenol
6. Nitrate
Updates in methods to human health-based chronic water quality standards
Amendments to Class 3 (Industrial Consumption) and Class 4 (Agriculture and Wildlife) standards.
Potential Water Use Classification Changes for Specific Water Bodies

Great Lakes Initiative Tier II Water Quality Criteria – Secondary Acute and Chronic Values

The Water Quality Guidance for the Great Lakes System, also known as the Great Lake Initiative (40 CFR 132), promulgated ambient water quality criteria that applied to waters in the Great lakes basin. The methodologies used to calculate these water quality standards were essentially the same as those used by US EPA since 1994 to calculate National Water Quality Criterion, with the addition of several new types of standards, such as wildlife-based criteria.

[Read more about GLI Wildlife-based Water Quality Criteria]

A minimum data set is required to calculate water quality criteria for both National and GLI (“Tier I”) standards. However, the GLI did provide for methodology States could use to calculate standards for other chemicals which may not have enough data to fulfill these minimum requirements. The resulting standards are referred to as “Tier II” values, or “secondary” values.

Under the GLI, if all minimum data requirements for calculating Tier I are not met, a “safety factor” or “adjustment factor” is applied to the existing data to calculate a water quality standard. All the same requirements for test data acceptability apply equally to Tier I and Tier II standards.

Because the Tier II values use conservative adjustment factors and assumptions, and rely on a limited data set, standards derived using Tier II methodologies will typically result in much lower concentrations compared to Tier I standards.

Monday, March 2, 2009

EPA Antidegradation Requirements Under MSGP-2008

The US EPA Multi-sector General Permit promulgated in 2008 (“MSGP-2008”) includes antidegradation requirements that apply to new and/or expanded discharges of stormwater from regulated industrial sites.

[What is an Antidegradation Policy?]

Regulation of discharges is based on three categories of waters:

Tier 2 Waters – Tier 2 waters are characterized as having water quality that exceeds the levels necessary to support propagation of fish, shellfish, and wildlife and recreation in and on the water.
Tier 2.5 Waters – For antidegradation purposes, Tier 2.5 waters are those waters designated by States or Tribes as neither Tier 2 nor Tier 3. States have special requirements for these waters. These waters are given a level of protection equal to and above that given to Tier 2 waters, but less than that given Tier 3 waters.
Tier 3 Waters – For antidegradation purposes, Tier 3 waters are identified by states as having high quality waters constituting an Outstanding Natural Resource Water (ONRW), such as waters of National Parks and State Parks, wildlife refuges, and waters of exceptional recreational or ecological significance.

Regardless of these general descriptions, the water bodies regulated under each tier must be LISTED by US EPA. The list of effected waters can change overtime. Currently, the States with listed waters include:

Tier 2 or 2.5: Massachusetts, New Hampshire, District of Columbia, Minnesota
Tier 3: New Hampshire, Puerto Rico, Minnesota, Wisconsin, New Mexico

Numeric Effluent Limits for Turbidity - Proposed New Source Performance Standard

On November 28, 2008, US EPA published its proposed revision to the federal requirements on stormwater discharges from construction sites. The key departure in the current proposal from existing requirements is the establishment of New Source Performance Standards (NSPS) and numeric effluent limit guidelines (ELG) that will apply to construction sites.

In June 2008, US EPA published its final general stormwater discharge permit for construction sites. US EPA’s intent is to issue a revised general permit once these new effluent limits are promulgated.

The current proposed rule addresses controls based on size of the construction site:

Less than 10 acres. Controls are similar to current approaches.
Greater than 10 acres. Sites greater than 10 acres will need to install temporary sediment basins meeting specific design criteria.
Greater than 30 acres. For large sites, discharges will need to monitor stormwater discharges and must meet a turbidity effluent limit of 13 nephelometric turbidity units (NTU). The effluent limit of 13 NTU is based on the determination that the Best Available Technology (BAT) has been demonstrated to meet this limit. In this case, the BAT is active treatment on-site using injection of polymer into the stormwater to improve precipitation of smaller particles.

Does this mean that all large construction sites will need to install active stormwater treatment systems? Not necessarily. Large sites subject to the effluent limit of 13 NTU will need to meet that limit. Sediment basins alone may not be capable of meeting this limit, and if so active treatment, including enhanced precipitation using chemical addition, may be required.

Once the US EPA finalizes the effluent limits for large construction sites, State general permits will likely include these permit limits as they are reissued. US EPA is accepting comments on the proposed Rule through February 26, 2009.

Pesticide Regulation Under Clean Water Act - Court Vacates NPDES Exemption

On January 7, 2009, an Appeals Court vacated a U.S. Environmental Protection Agency (EPA) rule that has allowed pesticides to be discharged to US waters without a National Pollutant Elimination System (NPDES) permit. As background, in November 2007 EPA had issued the final rule stating that pesticides applied in accordance with the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) are exempt from the Clean Water Act's permitting requirements.

The Clean Water Act regulates the discharge of pollutants into the nation's waters by, among other things, requiring entities that discharge pollutants to obtain a National Pollutant Discharge Elimination System (NPDES) permit. For almost thirty years prior to the adoption of the 2007 rule, pesticide labels issued under the FIFRA were required to contain a notice stating that the pesticide could not be "discharged into lakes, streams, ponds, or public waters unless in accordance with an NPDES permit".

The Appeals Court ruled that pesticide residues and biological pesticides constitute pollutants under federal law and therefore must be regulated under the Clean Water Act in order to minimize the impact to human health and the environment.

[Read an update on the Court ruling on NPDES permit requirement for pesticide applications]