Water Quality Standards And Classifications

Water Quality Standards are the basis for programs to protect the state waters. Standards set forth the maximum allowable levels of chemical pollutants and are used as the regulatory targets for permitting, compliance, enforcement, and monitoring and assessment of the quality of the state's waters. Waters are classified for their best uses (fishing, source of drinking water, etc.) and standards (and guidance values) are set to protect those uses.

The water quality standards program is a state program with federal (U.S. EPA) oversight. New York's longstanding water quality standards program predates the federal Clean Water Act and protects both surface waters and groundwaters.

U.S. EPA defines a water quality standard to include the criteria, the designated (best) uses of the water, and an antidegradation policy.

Information regarding the New York State Water Quality Standards Program can be found in state regulation, specifically New York Codes, Rules and Regulations Title 6 (6 NYCRR) and guidance documents found in the Division of Water Technical and Operational Guidance Series (TOGS). Contact Jason Fagel at [email protected], Chief, Standards and Analytical Support Section.

Standards and Criteria 

DEC establishes water quality standards and other criteria for many specific substances. These standards can be either narrative (e.g., "none in amounts that will impair ...") or numeric (e.g., "0.001 µg/L") and are found in NYS regulation 6 NYCRR Part 703. In the absence of established water quality standards, numeric guidance values are derived and compiled in Division of Water guidance (TOGS 1.1.1 [PDF]). Ambient standards and guidance values are supported by technical documents called "Fact Sheets" that are also available upon request.

Water Classifications and Reclassification 

All waters in New York State are assigned a letter classification that denotes their "best uses" (e.g., fishing, swimming, source of drinking water). Letter classes such as A, B, C, and D are assigned to fresh surface waters, and SA, SB, SC, I, and SD to saline (marine) surface waters. Best uses include: source of drinking water, primary contact recreation (i.e., swimming), secondary contact recreation (i.e., boating), fishing, and shellfishing. The letter classifications and their best uses are described in regulation 6 NYCRR Part 701. The classification of individual bodies of surface water is in regulation 6 NYCRR Chapter X (Parts 800 - 941).

Surface waters of the State are reclassified through the formal rule making process. Requests for reclassification can be made by submitting a completed Water Reclassification Request Form (PDF) to DEC at the address on the form or by using the "E-Mail Form" button at the top of the form.

All fresh groundwater in New York State is Class GA. The best use of Class GA groundwater and Class A, A-Special, AA, and AA-Special surface waters is a source of potable water supply. Standards and guidance values of the Health (Water Source) Type are established for these waters to protect this use. Separate standards for drinking water are promulgated by the New York State Department of Health (NYS DOH).

Reclassification of St. Lawrence River Drainage Basin

The Division of Water expects to propose upgrades to the classifications of certain surface waters in 6 NYCRR Part 910 (St. Lawrence River drainage basin). These reclassifications are necessary to meet federal Clean Water Act (CWA) goals for water quality and, if adopted, would result in higher classifications (and thus more stringent water quality standards) for some waters in this drainage basin.

Numerous Class D surface waters, which only provide protection for fish survival, would be proposed to be upgraded to higher classifications (Class C or higher), which are protective of both fish survival and fish propagation, and are fully consistent with the "fishable" goal of the CWA. When a water is upgraded from Class D to C (or higher), an additional set of water quality standards would apply to protect the water quality for fish propagation. These are more stringent than the standards for fish survival that apply to Class D waters. Certain waters would also receive protection for trout or trout spawning.

When the rule is proposed, DEC anticipates having one or more public information meetings within the St. Lawrence River drainage basin, along with a public hearing. Notification of the formal public process will be made via both the New York State Register and the Environmental Notice Bulletin.

Antidegradation 

New York has a statewide antidegradation policy as set forth in the September 9, 1985 Organization and Delegation Memorandum Number 85-40 (PDF). For the Great Lakes System, this statewide policy is supplemented by implementation guidance in TOGS 1.3.9 (PDF)

Other Resources

Standards and guidance values of other Types, including Health (Fish Consumption), Aquatic (Chronic), Aquatic (Acute), Wildlife, and Aesthetic are also established. Further information is provided in the Introduction to TOGS 1.1.1 (PDF).

Water quality standards and standard-setting procedures are in 6 NYCRR Chapter X, Parts 700-706.

Several Technical and Operational Guidance Series (TOGS) are relevant to water quality standards:

• TOGS 1.1.3 (PDF) - Procedures for derivation of site-specific standards and guidance values for protection of aquatic life.
• TOGS 1.1.4 (PDF) - Procedures for derivation of bioaccumulation factors.
• TOGS 1.1.5 (PDF) - Procedures for deriving ambient water quality standards and guidance values for the protection of wildlife.
• TOGS 1.1.6 (PDF)- Interpretation Guidance for Marine Dissolved Oxygen (DO) Standard.

Recreational Criteria Upgrades and Classification Updates for Saline Waters

 On July 27, 2022, NYSDEC issued an Advanced Notice of Proposed Rule Making (ANPRM) with the New York State Department of State. The ANPRM was a data gathering and public outreach exercise intended to inform future reclassification and water quality standard rule makings applicable to saline waters of the State. This ANPRM closed on November 28, 2022. 

On March 28, 2023, NYSDEC filed a Notice of Proposed Rule Making with the New York State Department of State to amend Parts 701 and 703 of Title 6 of the Official Compilation of Codes, Rules, and Regulations of the State of New York (6 NYCRR).

The proposed regulatory updates to 6 NYCRR Parts 701 and 703:

• water quality standards to protect the shellfishing best use in Class SA waters;
• protect the primary contact recreation best use in Class SA and SB waters;
• maintain water quality suitable for primary contact recreation in Class SC waters;
• protect the secondary contact recreation best use in Class I waters; and
• add a wet weather (WW) limited use designation for waters impacted by combined sewer overflow discharges.

The proposed rule making will impact Class SA, SB, SC, and I waters in and around New York City, Long Island, and the Lower Hudson Valley.

More information and details on how to attend the public hearing and submit comments are available on DEC's website.

Water Quality Guidance Values to Regulate PFOA, PFOS, and 1, 4-Dioxane

The finalized guidance values (GVs) are shown in the table below. The Department of Health (DOH) maximum contaminated levels (MCL) for finished drinking water are displayed for informational purposes.

The GVs were derived by procedures established in Title 6 of the New York Codes, Rules, and Regulations (NYCRR) Part 702. Learn more about these Emerging Contaminants.

Nutrient Criteria

New York, like many other states, is working with the United States Environmental Protection Agency (USEPA) to develop more specific numeric criteria that better define the levels of nutrients that result in impairment of water uses. Numeric criteria provide more definitive nutrient thresholds for the regulation of nutrients in NYS waters.

Nutrients: The Problem

Nutrients (phosphorus and nitrogen) are a natural part of healthy lakes, rivers, streams, and estuary ecosystems. However, excessive nutrients can cause water quality problems that negatively affect water supplies, recreational uses and aquatic life.

High levels of nitrogen and phosphorus in waters can produce nuisance algal blooms and increase aquatic weed growth.

Excessive algal and weed growth reduces:

• water clarity;
• recreational value of a waterbody;
• oxygen in the water; and
• can produce "dead zones" where dissolved oxygen levels drop so low that aquatic life cannot survive.

Point and nonpoint sources of nutrient enrichment and eutrophication to streams, lakes, and estuaries:

• Agricultural activities that result in animal waste and sediments washing into waterbodies.
• Urban runoff from impervious surfaces (parking lots, lawns, rooftops, roads).
• Inadequate onsite septic system.
• Municipal wastewater treatment plant discharges.
• Atmospheric deposition.

Current Standards

Nutrients are regulated in New York State Waters by a narrative water quality standard rather than a numeric standard. A numeric standard provides a specific numeric threshold (e.g., mercury not more than 0.0007 ug/L), and a narrative standard lays out a descriptive condition that needs to be met.

The narrative standard for phosphorus and nitrogen is: None in amounts that result in the growths of algae, weeds, and slimes that will impair the waters for their best usages.

Challenges

Developing specific numeric criteria for nutrients is complicated by a number of factors:

• Nutrients are naturally occurring and everywhere in our environment, so more stringent criteria are expected to affect many activities, stakeholders, and regulatory programs.
• Some level of nutrients is necessary for a healthy ecosystem and appropriate levels of nutrients vary from waterbody to waterbody, depending on a variety of characteristics (for example, depth, streamflow, water temperature, etc).
• Elevated nutrient levels by themselves do not normally cause direct impairment (except at extremely high levels), but rather they can produce conditions, such as reduced clarity, weed/algal growth, and low dissolved oxygen, that can impair aquatic life, water supplies and recreational uses.

Because of these complicating factors and the impact numeric nutrient criteria are likely to have across the state, New York is taking an intentionally deliberate approach to developing these criteria. DEC will evaluate and communicate the implications, to insure that the final plan will be effectively and successfully implemented.

Current Nutrient Reduction Efforts

The Numeric Nutrient Criteria will build on work that New York has already taken to reduce nutrients in lake, rivers, streams and estuaries:

• Total Maximum Daily Load (TMDL) plans are watershed-based pollutant reduction strategies that have been established for many high-profile nutrient-impacted watersheds, such as Lake Champlain, Susquehanna (Chesapeake Bay), and Long Island Sound.
• Municipal Separate Storm Sewer Systems (MS4) program requires practices to reduce nutrients and other pollutants from stormwater discharges and impervious surface runoff.
• Concentrated Animal Feeding Operations (CAFO) program requires best management practices to limit nutrient runoff from agricultural activity.
• The State Pollutant Discharge Elimination System (SPDES) regulates all discharges of wastewater to lakes, rivers and streams and requires all dischargers to meet standard treatment levels.
• Water Quality Based Effluent Limits (WQBELs) can require dischargers to reduce nutrients beyond standard treatment levels where necessary to protect water quality and recreational uses.
• Numeric guidance for total phosphorus, a value of 20 ug/L, is already in place for most lakes and reservoirs in the state.
• Dishwasher Detergent and Nutrient Runoff Law are in place banning phosphorus-based detergents and lawn fertilizers statewide.

NYSDEC is currently working to identify nutrient criteria values-initially focusing on phosphorus in fresh waters-that are protective of water quality in New York State. The Department is aware of the impact that more strict nutrient controls could have on the regulated community and will develop an implementation strategy that recognizes the need to phase in new criteria over time. We are working toward release of the scientific and technical basis for the draft specific criteria as well as related implementation plans sometime in 2013, with release of a formal nutrient criteria proposal possible in late 2013. As these efforts move forward, NYSDEC will conduct public outreach to inform stakeholders and solicit their feedback.

The current version of the New York State Nutrient Standards Plan (PDF) for the development of numeric nutrient criteria can be found on the NYSDEC website. This Plan, initially focusing on phosphorus in fresh waters, has been developed in consultation with, and mutually agreed upon by the USEPA. A Table of Milestones for Nutrient Criteria, revised June 16, 2015 addends and updates the milestones in the 2011 plan.

Tables of Milestones for Nutrient Criteria

New York's Plan to Revise and Expand its Nutrient Criteria Program

There are seven basic elements to New York State's approach:

1.a. Human Health - Lakes and Reservoirs
1.b. Human Health - Flowing Waters
2.a. Recreation - Lakes and Reservoirs
2.b. Recreation - Flowing Waters
3.a. Aquatic Life - Flowing Waters
3.b. Aquatic Life - Lakes and Reservoirs
4. Estuaries

The Table of Milestones (below) is revised to update dates and to more fully represent the full range of actions being conducted by New York State. This includes the work on the elements shown above.

*DEC believes that criteria for phosphorus in freshwaters should be the first priority for our limited resources, given that virtually all freshwater lakes and reservoirs are phosphorus-limited. Criteria will be developed for nitrogen in freshwaters as resources permit. Although nitrogen criteria have been drafted for aquatic life for rivers and streams, public release and proposal of these criteria will be aligned with other nitrogen criteria in the interest of consistency. (See section 3.b of this Nutrient Standards Plan, below for additional information.) For saline water estuaries, nitrogen is more typically the limiting nutrient. Therefore, criteria for nitrogen are a higher priority for estuaries, with criteria for phosphorus to be developed as resources permit.

**Dates reflect completion of DEC plan for implementation of nutrient criteria While DEC continues to work toward numerical nutrient criteria as resources and internal review allows, DEC will focus on a broad array of strategies to continue nutrient reduction consistent with EPA's March 2011 "Nutrient Reduction Framework" memo. DEC's broad efforts will support an implementation strategy based on existing narrative standards, and will include nutrient reductions via TMDLs, watershed plans, and appropriate regulatory measures in targeted priority waterbodies/watersheds. This will be expanded to include targets for nitrogen in estuarine waters as draft criteria are developed.
 

***Proposal of criteria is anticipated to occur approximately 6 months after completion of the regulatory impact assessment.