EPA WQS Handbook

Question 1

Describe ONRWs.

Answer 1

Outstanding National Resource Waters - they are provided the highest level of protection under the antidegradation policy.

Question 2

Describe how designated uses may be removed.

Answer 2

If a designated use is an “existing” use, the existing use cannot be removed unless a use requiring more stringent criteria is added (example: recreation use for wading being “upgraded” to swimming).

If a designated use isn’t an “existing” use, the use may not be removed unless the state can show that the use isn’t attainable.

Question 3

Name the components of WQS.

Answer 3

1. Designated uses.
2. Water quality criteria to protect the designated uses.
3. Antidegradation requirements.
4. General policies affecting the application and implementation of WQS, which states may include at their discretion (e.g. mixing zone, variance, and critical low-flow policies).

Question 4

When are states required to conduct a Use Attainability Analysis?

Answer 4

When the state doesn’t designated the uses listed in CWA 101(a)2 (fishable / swimmable).

Question 5

What is the difference between “toxic pollutants”, “priority pollutants”, and “pollutants with toxic effects”?

Answer 5

Toxic Pollutants - A list of specific pollutants regulated under CWA Section 307(a)(1).

Priority Pollutants - A subset of Toxic Pollutants (this sub-list was created in order to prioritize action on the pollutants).

Pollutants with Toxic Effects - Includes all pollutants that may have toxic properties.

Question 6

Describe the seasonality of designated uses.

Answer 6

Some designated uses may be specified as seasonal (for example: body contact recreation in northern climates).

Question 7

Briefly describe the different levels of the EPA’s Antidegradation Policy.

Answer 7

Tier 1 - This is the “bare minimum” level of protection. It protects existing uses.

Tier 2 - Protects “fishable swimmable” uses and other existing uses.

Tier “2 ½” - Between 2 and 3. Allows states to provide a very high level of water quality protection, without precluding unseen future economic and social development considerations.

Tier 3 - Applies to ONRWs.

Question 8

Explain the difference between MCLs and MCLGs.

Answer 8

Maximum Contaminant Level Goals = Health-based criteria ONLY.

Maximum Contaminant Levels = Health based criteria, but give consideration to the cost and technological feasibility of reducing contaminant levels in water to meet the standards.

Question 9

Define “waters of the United States”. Explain how this differs from “waters of the state”.

Answer 9

“Waters of the United States” has a complicated definition, but basically means navigable waters.

States may choose to expand their coverage of WQS beyond just waters of the United States. These additional waters and called “waters of the state”.

Question 10

Explain the difference between bioaccumulation and bioconcentration.

Answer 10

Bioaccumulation refers to the uptake and retention of a chemical by an aquatic organism from all surrounding media (e.g., water, food, sediment).

Bioconcentration refers to the uptake and retention of a chemical by an aquatic organism from water only.

For some chemicals, particularly those that are persistent and hydrophobic, the magnitude of bioaccumulation by aquatic organisms can be substantially greater than the magnitude of bioconcentration.

Question 11

How/when do “designated uses” apply to more than just the water body itself?

Answer 11

When designating uses, states are supposed to consider upstream and downstream effects.

For example, when downstream designated uses are changed, upstream jurisdictions will be required to help maintain the downstream standards.

Question 12

What is specified in 40 CFR 131?

Answer 12

40 CFR 131 describes the requirements and procedures for states to develop, adopt, review, revise, and submit WQS.

40 CFR 131 also describes the requirements and procedures for EPA to review, approve, disapprove, and promulgate WQS as authorized by CWA Section 303(c).

Question 13

What are the “minimum” designated uses that states must use, according to CWA 303(c)?

Answer 13

1. Public water supplies
2. Propagation of fish and wildlife
3. Recreation
4. Ag/Industrial purposes
5. Navigation

Question 14

What does “independent application” mean?

Answer 14

In making water quality management decisions such as Section 303(d) listing decisions, the EPA recommends that states apply each criterion independently to the particular water body. “Independent application” means that, where different types of assessment information are available (e.g., monitoring data for toxicity, water chemistry, and biology), any one assessment is sufficient to identify an existing or potential impairment regardless of the results from other types of assessment. For example, available information might not indicate an exceedance of a chemical-specific criterion to protect aquatic life, but the biological assessment at the site indicates the aquatic life use is not being met. In that case, for purposes of making a listing decision under Section 303(d), the state would list the water as impaired for the aquatic life use.

Question 15

Define UAA. When is it required?

Answer 15

Use Attainability Analysis. Definition: A structured scientific assessment of the factors affecting the attainment of a use, which may include physical, chemical, biological, and economic factors.

Required when:

1. the state designates or has designated uses that don’t include fishable/swimmable, OR
2. the state wants to remove a designated use

Question 16

What is specified in CWA Section 401?

Answer 16

Under CWA Section 401, states have authority to issue water quality certifications for certain federally permitted or licensed activities.

Question 17

When evaluating whether a provision constitutes a new or revised WQS, what 4 questions does EPA consider?

Answer 17

1. Is it a legally binding provision adopted or established pursuant to state law?
2. Does the provision address designated uses, water quality criteria (narrative or numeric), and/or antidegradation requirements for waters of the USA?
3. Does the provision express or establish the desired condition (e.g. designated uses, criteria) or instream level of protection (e.g. antideg requirements)?
4. Does the provision establish a new WQS or revise an existing WQS (as opposed to merely implementing a WQS)?

If the answer to ALL 4 of these questions is YES, then the provision would likely constitute a new or revised WQS subject to EPA review and approval.

Question 18

Name the objectives set forth in CWA Section 101(a).

Answer 18

1. Restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.
2. Wherever attainable, achieve a level of water quality that provides for the protection and propagation of fish, shellfish, and wildlife, AND recreation in and on the water.

Question 19

What is specified in CWA Section 304(a)?

Answer 19

CWA Section 304(a) contains US EPA’s National Recommended Water Quality Criteria. The list provides quantitative concentrations or levels of constituents that will generally protect a designated use of water.

304(a) criteria recommendations don’t impose legally binding requirements.