The Arid West Water Quality Research Project

1997 Conference

April 23-25, 1997

(Selected Conference Materials)

Chemicals of Concern Discussion Group

Chemical Criteria - by Benjamin Parkhurst, Ph.D.

I. Introduction / Outline

A. What are chemical criteria and how are they used in water quality management?

1. EPA ambient water quality criteria

2. State water quality standards

3. Site-specific water quality standards

B. Why is this area of research important for arid West ecosystems?

1. Predominance of ephemeral, effluent dominated, and intermittent waters.

2. Relative value of water in the arid West.

C. Classes of chemicals of concern

1. Conventional parameters

a. Dissolved oxygen

b. Temperature

c. pH

d. Suspended solids

e. Salinity

2. Toxic chemicals

a. Ammonia

b. Chlorine

c. Pesticides

d. Metals

Others

Chemicals of Concern (continued)

11. What are the primary issues?

A. Application to ephemeral, effluent-dominated and intermittent waters.

1. Definitions of ephemeral, and effluent-dominated, and intermittent waters.

2. What is different about these waters?

3. Designated use for these waters.

a. Aquatic and wildlife uses

b. Fish consumption

4. Use attainability analyses

a. Policy of independent applicability

b. Weight-of-evidence approaches for measuring use attainability

c. If uses are not being attained, then what are the possible causes?

i. Chemicals

ii. Other factors

5. Site-specific standards

a. Water effect ratios

b. Application to ephemeral, effluent dominated, and intermittent waters with limited aquatic communities.

6. Permit Limits

a. Compliance issues

b. Metal partitioning/translator studies

c. Endangered or threatened species

d. Stormwater

 

Chemical Group Meeting Notes

Session 1: Review of Conference Materials and Identification of Discussion Areas

As a starting point, the group utilized the initial list of Chemical Critical/Candidate issues that were provided to the conference attendees. Dr. Benjamin Parkhurst, President of HAF, Inc. and a Principal with The Cadmus Group, Inc. of Laramie, Wyoming, led the discussion group in a review of the list for the purpose of verifying issues and topics, eliminating issues and adding new topics to the list. Several key research areas were identified by the group participants and are summarized below:

1. Specific chemicals primarily are of concern in arid regions due to differences in designated uses, habitats, hydrology, water quality, and species for ephemeral, intermittent, and effluent-dependent waters. Therefore, research is needed to develop methods for deriving criteria and standards that reflect these differences.

Three water quality parameters that are of broad concern in the arid West that warrant research are dissolved solids, turbidity and total suspended solids.

Develop laboratory toxicity data for arid West species for use in expanding the national database to cover currently underrepresented species and to develop site-specific criteria, use designations and toxicity testing protocols.

2. Evaluate the influence of water quality in ephemeral, effluent-dependent and intermittent waters on site-specific standards. Important constituents include hardness, alkalinity, TOC, pH, temperature, TSS, and salinity.

3. Develop protocols for implementing hardness-dependent metals criteria in waters above 400 mg/L CaCO3.

4. Evaluate application of water quality standards to storm flows.

5. Quantify the fate and effects of effluents on groundwater quality.

6. Develop methods for evaluating risk to human health and wildlife from consumption of aquatic life in ephemeral, effluent-dependent and intermittent streams, drains, and canals.

7. Conduct an analysis of the standards and permitting process to determine the most cost-effective ways of developing more appropriate standards and limits for ephemeral, effluent-dependent and intermittent waters.

8. Develop protocols for evaluating magnitude, duration, frequency, and flows in ephemeral and effluent-dependent streams for TMDL, mixing zone, and effluent limit development purposes

Session 2: Prioritization of Research Areas and Needs

During Session 2, the group reviewed, refined, and prioritized the list of issues from Session 1. Each research topic was assigned a ranking of high, moderate or low priority pursuant to the group's perception of the importance of the research. Budget impact and fulfilling critical data needs in support of water quality standards for arid West streams resulted in the following:

High Priority Research/Study Topics

1. Research is needed to define appropriate designated uses, standards, and permit conditions that reflect the differences in habitats, hydrology, water quality, and species for ephemeral, intermittent, and effluent-dependent waters in the arid West. We recommend that a phased approach be used.

Step one: Conduct an analysis of the standards and permitting process to determine the most cost effective ways to developing more appropriate standards and limits for ephemeral, effluent-dependent and intermittent waters.

Step two: Conduct an analysis of protocols for evaluating magnitude, duration, frequency, and flows in ephemeral and effluent-dependent streams for TMDL, mixing zone, and effluent limit development purposes to determine the most cost-effective ways of modifying these to develop more appropriate values.

Step three: Design research to address the most cost effective ways of modifying standards and limits. Specific research topics may include the following:

• Two water quality parameters that are of broad concern in the arid West that may warrant research are dissolved solids and total suspended solids.
• Develop laboratory toxicity data for arid West species for use in expanding the national database to cover currently underrepresented species and to develop site-specific criteria, use designations and toxicity testing protocols.
• Risks of chemicals in these waters to threatened and endangered species.

2. Develop protocols for implementing hardness-dependent metals criteria in waters above 400 mg/L CaCO3.

3. Evaluate risks to human health and wildlife from consumption of aquatic life in ephemeral, effluent-dependent, intermittent streams, drains and canals.

4. Evaluate the influence of water quality in ephemeral, effluent-dependent and intermittent waters on site-specific standards. Important constituents include hardness, alkalinity, TOC, pH, temperature, TSS, mineralogy, and salinity.

Moderate Priority Research/Study Topics

Quantify and evaluate the fate and effects of effluents on groundwater and vadose zone quality.

Specific cases:

• Nitrogen species
• TDS
• Others

Low Priority Research/Study Topics

Evaluate application of water quality standards to storm flows.

Session 3: Discussion of Applicability of Research to Revised Water Quality Standards

The third breakout session for the chemical criteria discussion group focused on how results from research can and should be employed by regulatory agencies, such as the EPA, and how to improve regulations and permitting of water quality in effluent-dependent streams. During this discussion, the group identified several policy Research/Study Topics and other recommended activities for improving the applicability of new research data. These issues were ranked according to their perceived importance and need.

High Priority Research/Study Topics

1. Sensitivity Analysis of Regulatory Approaches

Research is needed to define appropriate designated uses, standards, and permit conditions that reflect the differences in habitats, hydrology, water quality, and species for ephemeral, intermittent, and effluent-dependent waters in the arid West. The group recommends that a phased approach be used.

• Step one: Conduct a sensitivity analysis of the process for determining designated uses, standards and permit limits to determine the most effective ways for developing more appropriate designated uses, standards and limits for ephemeral, effluent-dependent and intermittent waters. This analysis would include reviewing and evaluating key documents such as the Water Quality Standards Handbook, Technical Support Document for Water Quality Based Toxin Control, TMDL Manual, Permit Writers Guide, etc.
• Step two: Conduct an analysis of protocols for evaluating magnitude, duration, frequency, and flows in ephemeral and effluent-dependent streams for TMDL, mixing zone, and effluent limit development purposes to determine the most cost effective ways of modifying these to develop more appropriate values.

The product of these two steps would be identification of key policy, regulatory, and research issues that need to be addressed. The workgroup concluded that many of the critical policy and regulatory issues would have to be addressed before necessary research for some key issues could be identified. However, the workgroup identified one research project that could be used to provide data needed to support different designated uses, standards, and limits for effluent-dependent waters in the arid West. This project would evaluate relationships between water quality and biological communities in effluent-dependent waters in the arid West. Standardized methods would be used to measure aquatic and riparian communities, habitat quality, and water quality in representative samples of effluent-dependent waters throughout the arid West. The results would be used to characterize these systems and the relationships between water quality and biological diversity. It would be used to characterize the ecological benefits of different levels of water quality in the arid West. The results would be used to determine if different designated uses, standards, and permit limits are warranted in the arid West based on both ecological and cost considerations.

The workgroup also identified some specific research projects that should be considered that might have broad utility to the arid West, including the following:

2. The effects of total dissolved solids and turbidity and total suspended solids on aquatic life.

3. Evaluation of risks of chemicals in these waters to threatened and endangered species in comparison to risks from other stressors.

4. Develop protocols for implementing hardness-dependent metals criteria in waters above 400 mg/l CaCO3.

5. Evaluate risks to human health and wildlife from consumption of aquatic life in ephemeral, effluent-dependent and intermittent streams, drains and canals.

6. Evaluate the influence of water quality in ephemeral, effluent-dependent and intermittent waters on site specific standards. Important constituents include hardness, alkalinity, TOC, pH, temperature, TSS, mineralogy, and salinity.

7. Quantify/evaluate the fate and effects of effluents on groundwater and vadose zone quality. Specific cases:

• Nitrogen species
• TDS
• Others

8. Evaluate application of water quality standards to storm flows

Chemical Group Participants

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