Numeric Criteria Development

The information presented below gives a summary of state progress towards the development of numeric criteria. The information comes from EPA’s “State Adoption of Numeric Nutrient Standards (1998-2008)” report, current water quality standards, program activity measures, and nutrient criteria development plans. Links to the Vermont’s Nutrient Criteria Plan and state water quality standards are also provided.

• Existing Numeric Criteria
• Links to the Plan and Criteria
• Milestone Information

Existing Numeric Criteria

S = Statewide    W = For selected waterbody    N ⁄ A=Not Applicable

Note: See Statewide Criteria and Site-specific Criteria tabs for more information.

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Links to Numeric Nutrient Criteria Plan and Existing Nutrient Criteria

Plans:

• Nutrient Criteria Development Plan for the State of Vermont 2011
• Nutrient Criteria Development Plan for the State of Vermont 2002

WQS: Vermont Water Quality Standards
Vermont Department of Environmental Conservation: Rules Summary Exit

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Milestone Information

Milestone information updated July 2012.

TN: Total Nitrogen; TP: Total Phosphorus

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Statewide Criteria

The information on this tab shows EPA-approved nutrient criteria for Vermont’s waterbodies. The language presented below comes directly from state water quality standards and applies to all waterbodies within the state (unless a waterbody type or designated use is noted). Criteria applicable to specific waterbodies within the state can be found on the “Site-specific Criteria” tab. For more information, refer to the Vermont water quality standards.

The following information reflects Vermont’s water quality standards posted to the Water Quality Standards Repository as of November 2010 (EPA-approved May 2008).

Chapter 3 Determination of Criteria

Section 3-01 Water Quality Criteria and Indices – General

B. General Criteria

The following water quality criteria shall be achieved in all waters, regardless of their classification:

2. Phosphorus

a. All waters - general policy

In all waters, total phosphorus loadings shall be limited so that they will not contribute to the acceleration of eutrophication or the stimulation of the growth of aquatic biota in a manner that prevents the full support of uses.

b. Upland Streams

In addition to compliance with the general policy above, for all streams above 2,500 feet in elevation, total phosphorus shall not exceed 0.010 mg/L at low median monthly flow.

d. Lakes, ponds, or reservoirs that have drainage areas of less than 40 square miles and a drainage area to surface area ratio of less than 500:1, and their tributaries.

(1) In addition to compliance with the general policy above, there shall be no significant increase over currently permitted phosphorus loadings. Discharges to tributaries shall not increase in-stream conditions by more than 0.001 mg/L at low median monthly flow. Indirect discharges to lakes, ponds, or reservoirs shall not increase total dissolved phosphorus as measured in the groundwater 100 feet from the mean water level of the lake, pond, or reservoir by more than 0.001 mg/L.

(2) Applicable basin plans, other applicable plans, permit limitations, and other measures adopted or approved by the Secretary, may define “no significant increase” so as to allow new or increased discharges of phosphorus, only when the permit for such discharges provides for a corresponding reduction in phosphorus loadings to the receiving waters in question.

3. Nitrates

a. General Policy

In all waters nitrates shall be limited so that they will not contribute to the acceleration of eutrophication, or the stimulation of the growth of aquatic biota, in a manner that prevents the full support of uses.

b. Lakes, Ponds and Reservoirs not including Riverine Impoundments

Not to exceed 5.0 mg/L as NO₃-N regardless of classification.

c. All Other Waters

(1) Not to exceed 0.20 mg/L, as nitrate-nitrogen (NO₃-N) at flows exceeding low median monthly flows, in Class A(1) and A(2) waters above 2,500 feet altitude, National Geodetic Vertical Datum.

(2) Not to exceed 2.0 mg/L as NO₃-N at flows exceeding low median monthly flows, in Class A(1) and A(2) waters at or below 2,500 feet altitude, National Geodetic Vertical Datum.

(3) Not to exceed 5.0 mg/L as NO₃-N at flows exceeding low median monthly flows, in Class B waters.

6. Taste and Odor
None that would prevent the full support of any designated uses or existing use or have an adverse effect on the taste or odor of fish.

7. Color
None that would prevent the full support of uses.

Section 3-02 Class A(1) Ecological Waters

A. Management Objectives
Managed to achieve and maintain waters in a natural condition, compatible with the following designated uses:

1. Aquatic Biota, Wildlife, and Aquatic Habitat - consistent with waters in their natural condition.

2. Aesthetics - water character, flows, water level, bed and channel characteristics, and flowing and falling waters in their natural condition.

3. Swimming and Other Primary Contact Recreation - highest quality in waters, in their natural condition with negligible risk of illness or injury from conditions that are a result of human activities.

4. Boating, Fishing, and Other Recreational Uses - highest quality as compatible with waters in their natural condition.

B. Water Quality Criteria for Class A(1) Ecological Waters
The following water quality criteria shall be achieved in all Class A(1) ecological waters.

1. Turbidity - None in such amounts or concentrations that would prevent the full support of uses, and not to exceed 10 NTU (nepholometric turbidity units) as an annual average under dry weather base-flow conditions.

Section 3-03 Class A(2) Public Water Supplies

A. Management Objectives
Water managed for public water supply purposes to achieve and maintain waters with a uniformly excellent character and a level of water quality that is compatible with the following designated uses:

1. Aquatic Biota, Wildlife, and Aquatic Habitat - high quality aquatic biota and wildlife sustained by high quality aquatic habitat necessary to support their life-cycle and reproductive requirements.

2. Aesthetics - water character, flows, water level, and bed and channel characteristics consistently exhibiting aesthetic value.

3. Swimming and other primary contact recreation - in waters that pose negligible risk of illness due to conditions that are a result of human activities, but managed as necessary for consistency with use as a public water supply.

4. Boating, Fishing, and Other Recreational Uses - suitable for good quality boating, fishing, and other recreational uses.

5. Public Water Supplies - highly suited as a source for public water supply with disinfection, and filtration when necessary.

B. Water Quality Criteria for Class A(2) Public Water Supplies
The following water quality criteria shall be achieved in all Class A(2) public water supplies.

1. Turbidity - None in such amounts or concentrations that would prevent the full support of uses, and not to exceed 10 NTU (nepholometric turbidity units) as an annual average under dry weather base-flow conditions.

Section 3-04 Class B Waters

A. Management Objectives
Class B waters shall be managed to achieve and maintain a level of quality that fully supports the following designated uses:

1. Aquatic Biota, Wildlife, and Aquatic Habitat - aquatic biota and wildlife sustained by high quality aquatic habitat with additional protection in those waters where these uses were sustainable at a higher level based on Water Management Type designation.

2. Aesthetics - water character, flows, water level, bed and channel characteristics, exhibiting good aesthetic value and, where attainable, excellent aesthetic value based on Water Management Type designation.

3. Public water supply - Suitable for use as a source for a public water supply with filtration and disinfection.

4. Irrigation of crops and other agricultural uses - suitable, without treatment, for irrigation of crops used for human consumption without cooking and suitable for other agricultural uses.

5. Swimming and other primary contact recreation - suitable for swimming and other forms of water based recreation where sustained direct contact with the water occurs and, where attainable, suitable for these uses at very low risk of illness based on Water Management Type designation.

6. Boating, fishing and other recreational uses - Suitable for these uses with additional protection in those waters where these uses are sustainable at a higher level based on Water Management Type designation.

B. Water Quality Criteria for Class B waters
In addition to the criteria specified in ' 3-01 of these rules, the following criteria shall be met in all Class B waters:

1. Turbidity - The following criteria shall be achieved: a. In Cold Water Fish Habitat waters - None in such amounts or concentrations that would prevent the full support of uses, and not to exceed 10 NTU (nepholometric turbidity units) as an annual average under dry weather base-flow conditions; and b. In Warm Water Fish Habitat waters - None in such amounts or concentrations that would prevent the full support of uses, and not to exceed 25 NTU (nepholometric turbidity units) as an annual average under dry weather base-flow conditions.

Site-specific Criteria

The information on this tab shows EPA-approved site-specific nutrient criteria for Vermont’s waterbodies. Criteria on this page apply only to the waterbodies listed below. Criteria applicable to all waterbodies within the state are found on the “Statewide Criteria” tab. For more information, refer to the Vermont water quality standards.

The following information reflects Vermont’s water quality standards posted to the Water Quality Standards Repository as of November 2010 (EPA-approved May 2008).

Chapter 3 Determination of Criteria

Section 3-01 Water Quality Criteria and Indices – General

B. General Criteria

The following water quality criteria shall be achieved in all waters, regardless of their classification:

2. Phosphorus

c. Lake Champlain and Lake Memphremagog
(1) It is the policy of the State of Vermont to accomplish those net reductions in current phosphorus loadings to Lake Champlain and Lake Memphremagog that are necessary to achieve the in-lake total phosphorus concentration criteria specified in Table 3 below. To support this policy, the following requirements shall apply.

(2) In the watersheds of Lake Champlain and Lake Memphremagog, there shall be no significant increase over currently permitted phosphorus loadings. “No significant increase” may be defined by the Secretary, as part of the applicable basin plans, other applicable plans, permit limitations, or other measures to allow new or increased discharges of phosphorus, only when the permit for such discharges provides for a corresponding reduction in phosphorus loadings from other sources within the watershed of the same lake segment.

(3) All discharges into each of the lake segments identified below, or into tributaries within the basin, shall comply with the applicable basin plans, other applicable plans, permit limitations and any other measures adopted or approved by the Secretary reasonably designed to achieve the following criteria:

Table 3

The above criteria shall be achieved as the annual mean total phosphorus concentration in the photosynthetic depth (euphotic) zone in central, open water areas of each lake segment.