The Arid West Water Quality Research Project

1997 Conference

April 23-25, 1997

(Selected Conference Materials)

Whole Effluent Toxicity (WET) Discussion Group

Whole Effluent Toxicity

by Donald Mount, Ph.D. and Brian E. Munson, Consultant

Introduction / Outline

A. Accomplishments

1. Identified New Pollutants

2. Remedial action has not often required treatment

B. Problems

1. Implementation

a. Critical conditions

b. Statistics

c. Choice of dilution water

C. Regulatory Issues

a. One-time failures

b. Definition of public waters

c. Mixing zones

D. Laboratory Quality

Inexperience

Low bidders

Sketch reporting

II. Problems unique to arid West waters

A. Major ion problem

1. Affects species choice

2. Test medium

B. Intermittent stream flow

1. Duration

2. Classification

C. Implementation

1. Choice of critical flow

2. Species used

3. Mixing

4. Dilution water

5. Major ion

III. Admonition: Keep clearly in mind the distinction between issues of methods and measurements from regulatory implementation and legal requirements.

Issues Raised

• The number of chemicals causing problems is very limited, about one dozen of them comprise 80% of the problem. Mostly one specific class of waste (hospital waste) is the main problem.
• When the problem is known, it can be solved successfully.
• Dose Response Curve. Statistical problems associated with failure, one zero causes failure regardless of the rest of the values.
• Legal Problems can arise when a ditch fills with water.
• High rate diffusers vs. Toxicity. If diffusers cause more death of organisms than the pollutants, a different approach to water quality is warranted.
• There are problems with lab qualities.
• The ion problem in the arid west (calcium, chloride, sulfide, nitrate, potassium, and bicarbonate). Necessary for each to be reviewed, some are toxic even at very low levels.
• What is the significance of hardness and other ions in both the receiving water and effluent.
• How do you apply the results of WET testing to the receiving water when stream flow is intermittent.
• Research, Implementation, and Policy.
• What is critical flow?
• Mixing Zone - Implementation problem not related to WET testing. Is 7Q10 what we want if it is not appropriate?
• Major Ion Testing - Implementation technical issues vs. Implementation policy issues.
• The method (WET testing) and the policy shouldn't be confused, the method was not developed to be the policy and it does not have to be this way.
• What constitutes public waters?

Whole Effluent Toxicity (WET) Meeting Notes

Session 1: Discussion of Whole Effluent Toxicity (WET) Issues

The application of whole effluent toxicity (WET) testing to arid ecosystems, particularly effluent-dependent streams of the arid West, was the subject of this first breakout session. The session was moderated by Dr. Donald Mount, Vice President of AscI Corporation / Asci-Duluth Environment Testing Division, Duluth, Minnesota. Commencing with the list of proposed research topics provided to conference attendees, (Page 11 of this document) the participants focused on modifying the Whole Effluent Toxicity Critical/Candidate Issues list to eliminate issues they felt were less critical and add others that they felt were more pertinent to the problem as well as refine issue descriptions.

Issue 1 - Define what we are trying to protect

This topic is likely covered by other groups. It is important to understand in order to evaluate any relationships between test organism response and response of organisms/habitats to be protected. What organisms are being protected in stormwater flows?

Issue 2 - How does WET apply to each flow regime?

Issue 3 - How do we field-evaluate WET testing in arid ecosystems?

ephemeral

stormwater

effluent-dependent waters

There needs to be research that tests WET responses to natural background waters in the arid West and to identify the response due to anthropogenic contribution. Project funds should be set aside to identify contributions to WET responses from naturally occurring compounds. What is normal storm flow? Under what conditions is WET testing not appropriate? Does WET measure anything useful in effluent-dependent waters?

Issue 4 - How can WET be modified to replicate arid West conditions?

test species (local or national; surrogates for T&E)

water chemistry (standard water or local water)

Can WET tests be "recalibrated" using local species? Should terrestrial species be used as test organisms in dry washes? We should probably be considering relative risks to prioritize testing. What about the effects of source water quality that is different than receiving water quality (e.g., CAP water is higher in TDS than local waters)? Different models should be developed where a situation does not conform to the general WET model. A watershed approach could be used. WET was intended to be site-specific to take local conditions into account but has not been implemented as such.

Issue 5 - Identify test organisms and test attributes (exposure, etc.) for:

dry washes

ephemeral

perennial

effluent-dependent

Toxicity needs to be examined relative to exposure time; a seven-day test may have no relation to a two-hour event. It should be standard practice to culture test animals in water that is more typical of the site. Changes in basic water chemistry may create major stress.

Issue 6 - Look for ways in which WET testing needs to be modified to be more applicable to stormwater in the arid West.

Why conduct WET testing on stormwater in the first place? Does stormwater really pose a risk? It seems that it would if toxics are present, but for the most part the impacts are physical. What is the appropriate response if a WET test shows toxicity? Will BMPs be acceptable?

Session 2: 2 2

Brian Munson of Dames & Moore, Inc., Phoenix, Arizona moderated sessions 2 and 3. In Session 2, the discussion group continued to refine the issues to more accurately deal with the needs and application of whole effluent toxicity testing for arid West streams.

Issue 1 - Define what we are trying to protect (including T&E and native species of concern).

We should be looking beyond typical habitats and species and identify those of special concern.

Issue 2 - Determine appropriate use of WET testing in ephemeral and effluent-dependent ecosystems by:

• Performing field studies to evaluate applicability of WET testing to arid ecosystems. Focus on ephemeral, intermittent and effluent-dependent streams, which receive stormwater and/or effluent
• Identifying how WET testing can be modified to replicate arid West conditions?

  test species

  water chemistry (impact of different water sources)

  water physical characteristics (temp, pH, NH3)

  correlate surrogate tests with native species

  modify protocols to allow ceridaphs/flatheads to be more tolerant of arid Western waters.

• Looking for ways in which WET testing needs to be modified to be more applicable to stormwater in the arid West.

Should we look at local species as indicators? How appropriate is WET testing for impacts to native species? Are there places where WET testing is not appropriate, and, where it is appropriate? And how is it best applied? How do you determine applicability or appropriateness? Is there a threshold community for which WET is appropriate? A suggested approach is to first determine whether an aquatic community is present and, if one is, the WET test is appropriate. An ammonia test should be developed to be applicable to local conditions. Researchers have also noted differences in test organism susceptibility to TDS, which can vary from place to place.

Issue 3 - Identify test organisms and test conditions (e.g., appropriate exposures, pH, and temperature) for:

dry washes

ephemeral streams

perennial

effluent-dependent waters (including created wetlands)

playas

Issue 4 - Native species of concern - develop evaluations of WET as it relates to native species, including T&E species.

Develop appropriate translators (different end points of effluent) for each species for arid species. It may be difficult, however, to develop end points for individual components for a test that involves a mixture.

Issue 5 - Determine WET testing variability and identify procedures (e.g., Method Detection Limit [MDL], Practical Quantification Limit [PQL]) to evaluate variability for compliance purposes.

This is a national issue and potentially not appropriate for this Project. However, issues related to dose response (stormwater) and culture issues for test organisms warrant its inclusion. If a control WET test indicates mortality, then the interpretation of results should be modified. Use of control in tests tries to address variability, but may not address specific arid West concerns.

Issue 6 - What factors should be considered in determining whether an aquatic community or terrestrial species is present for which WET testing is appropriate.

In order to apply the test, a series of factors should be evaluated such as whether a discharge will flow into a perennial water, habitat for wildlife, fishery, etc.

Issue 7 - Identify water characteristics, contaminants and species that are common to large areas of the arid West to aid in protocol selection.

The arid West has different water characteristics that need to be identified and evaluated. It may be possible to find species that are appropriate for a wider area. Although they have slacked off somewhat in their monitoring efforts, USGS data may be valuable in addressing this issue.

Issue 8 - Develop a practical means to determine natural background levels of contaminants of concern.

It would be good to have data from undisturbed watersheds to establish a baseline. Where practical, this baseline should be developed for undisturbed watersheds near to and comparable to urban watersheds being tested. A regional list of unique background levels of water constituents (e.g., Cu, organics) should be compiled to characterize receiving waters and reviewed to see how it applies to WET. We need to be careful not to lump dissimilar ecosystems. Source water should be examined. This approach might facilitate topics that are local compliance problems (e.g., naturally occurring copper).

Session 3: Prioritization of Issues and Implementation of Research

The focus of Session 3 was to prioritize the issues discussed in the previous sessions with further discussion on implementation. Comments have been added to specific issues to clarify the purpose of that particular issue as discussed at this session.

High Priority Research/Study Topics

Issue 1 - Define what we are trying to protect (including T&E and native species of concern).

This issue is not really central to the focus of the WET group, although it is critical with respect to application and interpretation of the test. It is suggested, and it is likely, that this will be a high priority for one of the other groups (habitat or biological).

Issue 2 - Determine appropriate use of WET testing in ephemeral and effluent-dependent ecosystems by:

a. Conduct field studies to evaluate applicability of WET testing to arid ecosystems. Focus on ephemeral, intermittent and effluent-dependent streams, which receive stormwater, and/or effluent.

b. Ascertain whether there are modifications to WET testing to better represent arid West conditions.

different test species

water chemistry (impact of different water sources)

water physical characteristics (temp, pH, NH3)

correlate surrogate tests with native species

modify protocols to allow ceridaphs/flatheads to be more tolerant of arid Western waters (may include rearing methods).

It should be clear that this is seeking to find different test species that better represent the arid West. Academicians and ASTM may have other protocol species. There is a concern that stormwater issues may have been lost in identifying research issues, although stormwater is a focus of Issue 2.a. There are national issues with the WET test, like proper dose response and problems with interpretation of the test. This research should focus on those issues that are unique to the arid West. Ammonia has created problems with WET testing in many cases, perhaps there should be a standard for ammonia in lieu of WET toxicity.

Issue 3 - Identify test organisms and test conditions (e.g., appropriate exposures, pH, and temperature) for:

dry washes

ephemeral streams

perennial

effluent-dependent waters (e.g., created wetlands)

playas

Moderate Priority Research/Study Topics

c. Look for ways in which WET testing needs to be modified to be more applicable to stormwater in the arid West.

Issue 4 - Native species of concern (including T&E species)

- evaluate the use of WET as it relates to the protection of native species, including T&E species.

Research on WET effects on native species is being done in other parts of the country. Native candidate species and WET test species for arid regions should be identified and prioritized.

Issue 5 - Determine WET testing variability and identify procedures (e.g., MSD, MDL, PQL) to evaluate variability for compliance purposes.

EPA indicates that there is research in progress on this issue, including studying salt (ions) effect on WET testing and salt tolerances for WET species.

Issue 6 - What factors should be considered in determining whether an aquatic community or terrestrial species is present for which WET testing is appropriate.

It is not clear that this issue will be of much help for state implementation. This issue is important if there are different kinds of water that need different levels of protection. Definitions of fishable and swimmable and use designations are institutional concerns to work with. Even if there are different designations, they will likely be aquatic habitat and will be protected. Is it possible that a dry aquatic habitat is not protected and therefore does not need to be tested? Silver City, New Mexico does not do WET testing because the effluent disappears within 200 meters of discharge and does not reach perennial streams.

Issue 7 - Evaluate use of WET testing to determine natural background levels of contaminants of concern.

This issue should probably also emphasize stormwater and the importance of background comparisons for urban watersheds.

Low Priority Research/Study Topics

Issue 7 - Identify water characteristics, contaminants and species that are common to large areas of the arid West to aid in protocol selection.

IMPLEMENTATION OF RESEARCH

Implementation should occur through regulations, standards and guidelines appropriate to the issue.

Barriers to Implementation

• federal, state and local agency buy-in
• be sure that EPA will accept the results of the research or it will be wasted. Sometimes states and EPA will not agree.
• resistance of advocacy groups
• be sure that environmental groups get information since they were invited and did not attend.
• toxicity is an emotional issue
• use of WET as an effluent limitation

Methods to address barriers

• outreach and training (dischargers and regulators) to explain results of research
• need to bring the state and EPA along with respect to research results as best we can and provide them with the best information
• peer review of process (scientific publication) will be critical to buy-in
• presentation of results at scientific conferences will help with outreach efforts

Whole Effluent Toxicity (WET) Group Participants

FINAL SESSION

The final session of the Conference presented a summary of the results of Session 3 for each topic to the entire group of Conference participants.

• Dr. Linwood Smith presented the findings of the Habitats of Concern discussion group (Pages 23 - 26 of this document).
• Dr. Richard Meyerhoff presented the findings of the Biological Criteria group discussion (Pages 40 - 41 of this document).
• Dr. Benjamin Parkhurst presented the findings for the Chemical Criteria discussion group. (Pages 49 - 50 of this document).
• Brian Munson presented the findings of the Whole Effluent Toxicity (WET) discussion group. (See Pages 56 - 58 of this document).

After a brief question and answer period, the Conference ended with a preview of future activities and closing remarks.

Future Activities

Ed Curley, Special Projects Program Manager for the Pima County Regional Wastewater Reclamation Department outlined the activities planned for the coming year. He noted that the Regulatory Working Group (RWG) would be meeting immediately after this session and several subsequent times during the next year to review the research proposed along with the reactions and recommendations that came out of this Conference. From the RWG meetings, a research agenda would be formulated. Requests for Proposals and contracts for research would be the next step. The next Conference would be held in 1998 to detail the research activities in progress and allow participants to comment on the ensuring projects and propose additional ideas for future research.

Mr. Curley gave a special thank you to the moderator/speakers, the technical support persons, and the note-takers who did such an excellent job in taking notes and finalizing them so quickly for each session. He also commended the Pima County support staff for their efforts and assistance in making this a successful conference.

Closing Remarks

George A. Brinsko, Director, Pima County Regional Wastewater Reclamation Department, made the closing remarks in which he thanked the conference participants for their active participation in the discussion groups. He particularly emphasized that it was important to note what needed to be protected in arid environments and take whatever appropriate actions were called for. Mr. Brinsko noted that agencies and regulators throughout the West were counting on the results from the WQRP.

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