SURFACE WATER TRIENNIAL REVIEW

What is a Surface Water "Triennial Review?"

Every three years the State is required by the Federal Water Pollution Control Act (Clean Water Act) to review its surface water quality standards and classifications to determine if changes are needed and, if necessary, to make those changes. The Clean Water Act also requires review of existing variances to surface water quality standards. This review process is called the "Triennial Review." What immediately follows is information pertinent to the current Triennial Review; past Triennial Review documents can be found at the bottom of this page.

2008 - 2010 Triennial Review

North Carolina’s surface water quality standards (15A 2B .0100 and .0200) (click here to download) were carefully reviewed to assure full compliance with Clean Water Act requirements and to ensure protection of North Carolina’s fresh and salt waters. Staff monitored US EPA websites and Federal Register notices for toxicological updates to chemical parameters that could be found in NC waters. Standards for dissolved metals, chlorophyll a, and 2,4 D are proposed for modification during the Triennial Review 2008-2010 process. 

Division of Water Quality Planning Staff presented proposed amendments to the Water Quality Committee of the Environmental Management Commission (EMC) on January 13, 2010. Staff requested permission to proceed to the EMC to request permission to hold public hearings on these proposed rule amendments. The Water Quality Committee approved the motion to proceed to the EMC in accordance with State and Federal requirements. On March 11, 2010, staff presented the proposed rule amendments to the full EMC and requested permission to hold public hearings on the proposals.  The EMC approved the motion to proceed to public hearings with the proposed rules.

DOWNLOAD: Proposed Amendments

Public hearings for the proposed rules may not be held until a fiscal analysis detailing estimated impacts from these proposals is completed by the Division of Water Quality and approved by the Office of State Budget Management.  Division staff are currently requesting cost and benefit information from potentially affected parties in order to facilitate this process.  This request from Division staff for information on the fiscal impacts of the proposed rules can be found through the following link:

DOWNLOAD: DWQ Request for Information

The Division has also assembled some tools and guidance documents meant to aid affected parties in determining the potential fiscal impacts of the proposed rules.  The following links provide information for point source and stormwater permit holders as well as for pretreatment programs.  Staff contact information can also be found through these links.

NPDES Dissolved Metals Limit Calculators (under “Quick Links”)

Stormwater Benchmarks

Pretreatment Facilities

PLEASE NOTE: The deadline for submission of information for inclusion in the Division’s fiscal analysis is September 7, 2010.

Chemicals Currently Being Examined: 

Metals

• Summary of Proposed Metals Changes
  Proposed revisions to metals standards are summarized in the attached “Metals Summary Table” for quick reference. Modifications to standards reflect updates to National Recommended Water Quality Criterion (NRWQC); revision of metals standards to reflect, where appropriate, the dissolved metal concentration; the addition of acute and chronic standards, and the use of a statewide hardness value of 25 mg/L to derive standards for hardness dependent metals.
   
• National Recommended Water Quality Criterion Updates
  Staff has compared the most current US EPA NRWQC values for metals to existing North Carolina standards and identified parameters requiring modifications. For example, where newer toxicity information is available, then that information is being incorporated into the NC standards. 

• Dissolved Metals
  Freshwater and saltwater criteria for most metals can be expressed as the total recoverable metal or the dissolved metal in the water column. With the exception of Mercury and Selenium, which are both bioaccumulative metals, the State proposes changing from total recoverable metals to dissolved metal water quality standards. The dissolved fraction more closely estimates the portion of the metal that is toxic to aquatic life. 
  
  Dissolved metals are calculated by using the applicable aquatic life criteria expressed in terms of total recoverable metal, and multiplying it by a conversion factor. A conversion factor accounts for the laboratory testing differences used to establish the original federal aquatic life criteria. The Conversion Factor for each metal can be viewed at the US EPA website, see “Appendix A - Conversion Factors for Dissolved Metals”
  
  
• Acute and Chronic Aquatic Life Standards
  Current aquatic life water quality standards for metals are chronic standards. Chronic standards offer protection from toxic effects resulting from longer-term exposure to a chemical. Addition of standards protective of acute (or short term) exposure will be proposed. Incorporation of standards for “acute” impacts will allow removal of the "maximum permissible level" language from the aquatic life standards (15A NCAC 02B .0211(3)(l) and 15A NCAC 02B .0220(3)(m)). An acute standard will be expressed as an average of two or more samples collected within one hour. Chronic standards will be expressed as a minimum of four samples taken on consecutive days, or as a 96 hour average concentration. Selenium and Mercury will not have acute standards recommended. (See below for additional information on these two metals).
   
• Hardness Dependent Metals
  Various components of water quality such as naturally occurring organic matter, pH, hardness, alkalinity and sodium can affect metal toxicity. When evaluating the toxicity of metals to aquatic life, “hardness dependent” means that the toxicity of the chemical increases as the hardness of the receiving water decreases. The EPA establishes hardness dependent water quality standards for the protection of freshwater aquatic life for the following metals: Copper, Zinc, Cadmium, Nickel, Chromium III, Silver and Lead. The State has previously assigned a statewide hardness of 50 mg/l. This value equaled the mean of hardness data collected by the Environmental Sciences Section of the Division of Water Quality.
  
  Because the water hardness can vary throughout the state, staff reviewed analytical hardness values for subbasins within the state to assure protection of sensitive species as directed by national protocol. This data evaluation indicates that a significant portion of the state periodically has hardness values equal to or less than 25 mg/L. Therefore, staff recommends numerical standards for hardness dependent metals at a state wide hardness of 25 mg/L. In addition, the proposed regulations include hardness dependent equations to allow flexibility for other hardness values to be applied. Application of the equations requires the incorporation of hardness values based on the tenth percentile of data collected within the local US Geological Survey (USGS) 8-digit Hydrologic Unit (HU). The equations are applicable for instream hardness ranges from 25 mg/l to 400 mg/l, expressed as CaCO3 or Ca+Mg. Alternative concentrations derived in this manner must be protective of downstream uses in accordance with State regulations. 
  
  The US EPA continues to examine the impact of other water quality components on metals toxicity. They have published only one revised criterion, for copper, which establishes a model used to determine copper toxicity based on a broad set of water quality parameters. The State will propose allowance for the use of the Copper Biotic Ligand Model in accordance with this revised federal criterion.
   
• Naturally Occurring Iron
  North Carolina is proposing to remove the standard for iron. Iron is a naturally occurring metal in the sediments and groundwater of the state.
   
• Attainment of Aquatic Life Uses
  The State proposes regulatory language relating to the demonstration of aquatic life use attainment with respect to metals standards. 

Chlorophyll a

Proposed modifications to the chlorophyll a standard include (1) clarification to the frequency of exceedence component and (2) addition of a regional specific standard for mountain and upper piedmont waters which are defined by 15A NCAC 02B .0202.

Portions of the proposed language for fresh and salt waters are as follows: 

(.) classified trout waters: not greater than 10% of data shall exceed 15 ug/L; 

(.) mountain and upper piedmont waters, defined by 15A NCAC 02B .0202: not greater than 10% of data shall exceed 25 ug/L;

(.) all other fresh surface waters: not greater than 10% of data shall exceed 40 ug/L; 

(.) not greater than 10% percent of data from any portion of sounds, estuaries and other waters subject to growths of macroscopic or microscopic vegetation shall exceed 40 ug/L. 

Note: Additional information with respect to these proposals is located on the "Surface Water Standards" page.

Information with respect to chlorophyll a proposed revisions may be obtained from Nikki Remington at (919) 807-6413, or by e-mail to Nikki.Remington@ncdenr.gov. 

2, 4 D (chlorophenoxy herbicide)

The US EPA Integrated Risk Information System (IRIS) has information with respect to the non-carcinogenic effects of 2, 4 D. North Carolina is proposing to revise the human health standard applicable to water supplies, currently 100 ug/L, to include this toxicity information. Incorporation of the new information results in a reduction in the water supply standard to 70 ug/L. 

These Parameters were Reviewed but are Not Proposed for Revision or Addition at this Time:

Mercury

No numeric revisions to concentrations are proposed at the present time.

In January of 2001, the US EPA published revised national criteria for methyl mercury concentrations in fish tissue. Because mercury bioaccumulates in the aquatic environment, the US EPA believes that measurement of fish tissue concentrations may be a better indicator for the protection of people who consume fish and shellfish. This criterion marks EPA's first issuance of a water quality criterion expressed as a fish and shellfish tissue value rather than as an ambient water column value. Assessing compliance with this new and revised fish tissue criterion required the US EPA to investigate and publish guidance on the implementation. This guidance was issued in January of 2009. Under new executive administration, a White House memo has placed all recently published guidance under Executive review. North Carolina will continue to monitor EPA's website for appropriate updates to Mercury for use in a future Triennial Review. Links to additional information: http://www.epa.gov/ost/criteria/methylmercury/document.html 

Selenium

No numeric revisions to concentrations are proposed at this time.

The US EPA is revising its NRWQC for selenium that is anticipated to be expressed as a fish tissue concentration rather than a water concentration. Like Mercury, the EPA is also developing guidance on how to implement this fish tissue criterion within the framework of traditional water quality management programs.  EPA expected to re-propose the revised selenium criteria as a draft for scientific views in 2009, with final criteria anticipated in 2010. Once published, NC will review the criteria and the accompanying implementation guidance for potential revisions to its standards. 

Acrolein

IRIS updated information relating to the non-cancer effects of Acrolein in June of 2003. To date, the US EPA has not revised the NRWQC to reflect this revised toxicity information. North Carolina does not currently have any permittees with known discharge of this chemical. Staff has determined that no immediate need exists for this chemical to be added to the regulations.

Ammonia

On July 8th, 2004, the US EPA notified the public in the Federal Register (69 FR 41262) of intent to re-evaluate the current aquatic life criteria for ammonia in response to recent studies suggesting that some freshwater mussel species may be more sensitive to ammonia exposure than the aquatic organisms considered in deriving the existing National ammonia criteria. To date, EPA has not made any final decisions on what to do about the ammonia criteria, and will not do so until all issues, questions and new scientific information is explored. North Carolina will continue to review publications as they become available. 

Atrazine

The State is currently reviewing activities by the US EPA and the Federal Insecticide, Fungicide, and Rodenticide Act Science Advisory Panel (FIFRA SAP) toward potential addition of a standard for Atrazine. EPA has not released draft Atrazine criteria for public review. North Carolina will continue to monitor the development of revised criteria for application within the State and make recommendations during future Triennial Review updates. 

Bacteria

Staff of the Division of Water Quality maintains on-going contact with EPA Region IV staff for updates that may affect freshwater and saltwater recreational bacteria standards. EPA is conducting research and criteria support studies within both the Office of Research and Development and the Office of Water. These activities will allow EPA to build a strong scientific foundation for up-to-date recreational water quality criteria, which EPA estimates it will publish in 2012. The new or revised criteria will replace the current criteria recommendations issued in 1986. The criteria are designed to protect people from illness associated with fecal contamination in water. No revisions to inland freshwater or saltwater bacterial standards are proposed for this Triennial Review timeframe. 

Cyanide

The Water Environment Research Foundation (WERF) published a document entitled “Scientific Review of Cyanide Ecotoxicology and Evaluation of Ambient Water Quality Criteria” in 2007. It provides a recalculation of the cyanide water quality criteria for the protection of aquatic life originally derived in EPA’s 1984 document “Ambient Water Quality Criteria for Cyanide”. Staff received questions from the Commonwealth of Virginia staff about the potential for revisions to the NC standards using the information in the WERF document. Staff used the WERF document’s freshwater and saltwater criteria and recalculated protective levels using a data set more specific to North Carolina. North Carolina’s current 2B cyanide standards are in line with WERF’s recalculated criteria, as well as the EPA’s current nationally recommended criteria. No changes are recommended at this time. 

Phenol

Currently, North Carolina has a narrative standard for phenolic compounds. Due to the odor/taste issues associated with phenol, permits are issued using 300 ug/L, the NRWQC for organoleptic effects. IRIS updated toxicity information with respect to the non-carcinogenic effects of phenol in 2002. The US EPA published, by Federal Register notice, revised NRWQC for human health protection to reflect this information on June 10, 2009. NC’s current approach, control of chemical contaminants causing unpleasant taste and odor in both fish and water supplies, is more stringent than the health effects of the chemical upon ingestion. North Carolina does not recommend any changes to the existing narrative standard for phenol. 

Toluene

IRIS updated toxicity information with respect to the non-carcinogenic effects of Toluene in 2005. To date, the US EPA has not updated its NRWQC for human health protection to reflect this information. North Carolina’s current water quality standards for the protection of freshwater aquatic life (11 ug/L) and protection of trout (0.36 ug/L) are protective of both aquatic life and human health, as aquatic life is more sensitive to the effects of toluene than are humans. North Carolina does not recommend any changes to the existing NC water quality standards for toluene. 

Estimated Schedule 2008-2010 Triennial Review of Surface Water Quality Standards

• January 2009 – Early Fall 2009: Public presentations and information sessions, request for public input
• June – November 2009: Develop draft rule package for Departmental review
• September 2009: Triennial Review Information Item for the Environmental Management Commission (EMC)
• November 2009: Draft revisions to Chlorophyll a standards for fresh and salt waters presented to the Water Quality Committee of the EMC
• January 2010: Triennial Review recommendations to the Water Quality Committee of the Environmental Management Commission (EMC); Request permission to proceed to the full EMC 
• June 7, 2010: Public request for information to be incorporated into fiscal analysis
• September 7, 2010:  Deadline for submission of cost and benefit information for inclusion into fiscal analysis
• June 2010 – ?: DWQ development of Fiscal Note, timeline dependent on Office of State Budget Management (OSBM) approval
• Steps after OSBM Fiscal Note approval:  

  1. North Carolina Register notification, Public Hearings and 60 day Comment Period 

 2. Review of comments received; Hearing Officers prepare response to comments and prepare report for EMC 

 3. Hearing Officer’s Report and recommendation to EMC. Pending approval by EMC to adopt proposed rule, rules submitted to Office of Administrative Hearings, Rules Review Commission (RRC). 

 4. Rule reviewed by the RRC. 

 5. Submittal of revisions to US EPA; US Fish and Wildlife Endangered Species Consultation; Request federal approval of revised NC water quality standards

Submit Your Comments

The Division of Water Quality, on behalf of the Environmental Management Commission, welcomes all comments related to these proposals.

Please e-mail your name, affiliation, address, telephone number and comments to Connie.Brower@ncdenr.gov. Written comments may be submitted to the following address:

ATTN Connie Brower
DWQ PLANNING SECTION
N.C. DEPT. OF ENVIRONMENT & NATURAL RESOURCES
1617 MAIL SERVICE CENTER
RALEIGH  NC  27699-1617

Past Triennial Reviews

• DOWNLOAD: 2004 - 2006 Surface Water Triennial Review Part ONE, Part TWO, Part THREE
• DOWNLOAD: 2000 - 2003 Surface Water Triennial Review

Last Updated: June 16, 2010