Whole Effluent Toxicity WET 22nd Annual Pretreatment Seminar North Little Rock, Arkansas August 9, 2

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Whole Effluent Toxicity (WET) 22nd Annual
Pretreatment SeminarNorth Little Rock,
ArkansasAugust 9, 2006Phillip Jennings,
6WQ-PPNPDES Toxicity CoordinatorUS
Environmental Protection Agencyjennings.phillip
_at_epa.gov214 / 665 - 7538
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What is WET?? (Whole Effluent Toxicity
/ Biomonitoring) WET, or biomonitoring, is the
use of live test organisms to determine the
potential toxic impacts of wastewater effluents,
stormwater, or other water discharges, on aquatic
life in receiving streams and lakes.
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What are YOU lookin at..or trying to protect?
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Is WET required? If so, why?
EPA and States require WET testing to ensure
compliance with objectives of the Clean Water
Act, federal regulations for NPDES permitting 40
CFR 122.44(d)(1), and State narrative water
quality standards to protect aquatic life.
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NPDES Permitting Regulations 40 CFR
122.(d)(1)(v)
Except as provided in this subparagraph, when the
permitting authority determines, using the
procedures in paragraph (d)(1)(ii), of this
section, toxicity testing data, or other
information, that a discharge causes, has the
reasonable potential to cause or contributes to
an in-stream excursion above a narrative
criterion within an applicable State water
quality standard, the permit must contain
effluent limits for whole effluent toxicity.
Limits for whole effluent toxicity are not
necessary where the permitting authority
demonstrates in the fact sheet or statement of
basis of the NPDES permit, using the procedures
in paragraph (d)(1)(ii), of this section, that
chemical-specific limits for the effluent are
sufficient to attain and maintain applicable
numeric and narrative State water quality
standards.
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State Water Quality Standard for the Protection
of Aquatic Life
After allowing for mixing with receiving water
upstream, there shall be no chronic toxicity
outside the edge of the defined mixing
zone. Chronic Toxicity Toxicity which, after
long-term exposure, exerts sublethal negative
effects, or which is lethal to representative,
sensitive organisms.
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Cuyahoga River Cleveland, Ohio
June 22, 1969
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Pretreatment Primary Defense

• Can add additional levels of protection and
  influent/effluent control
• User survey analysis when performing a Toxicity
  Reduction Evaluation (TRE)
• Initial points of reference outside POTW
• Systematic examination of collection system

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Facility-Specific Information

• Industrial waste surveys
• Industrial user self-monitoring reports
• Industrial user operational schedules and flow
  patterns
• Waste hauler monitoring and manifests
• Hazardous waste inventories

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System Inspections/Sampling

• System inspections
• Microtox, ELISA
• Streamlined WET tests
• Onsite facility inspections
• Advance notice to users

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Detective Work

• What else is going on? Are there records that
  correlate WWTP / SIU activities and
  reduced/increased toxicity?
• Develop chemical usage profile for SIUs
• Batch or seasonal processes/chemicals?
• Communicate
  Communicate
  Communicate

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Toxicity Reduction Evaluations

• The first step in a TRE is to gather all
  information and data that may relate to effluent
  toxicity and that might prove useful in planning
  and conducting the TRE. This information can be
  categorized as POTW treatment plant data and
  pretreatment program data. The pertinent POTW
  information includes historical effluent toxicity
  data as well as information on the treatment
  plants design capabilities, treatment
  performance, and operation and maintenance
  practices. Appropriate pretreatment program
  information consists of IWS data, industrial user
  permits, pretreatment inspection reports, and
  monitoring and compliance reports.

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Local Limits

• The goal in developing local limits is to
  implement pretreatment regulations that are
  technically and legally defensible. The local
  limits can include provisions for equitable
  recovery of costs associated with the toxicity
  source evaluations and local limits development.

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Permit Requirements

• Pretreatment permit requirements resulting from
  Toxicity Reduction Evaluation studies -
• WET Testing
• Chemical-use Inventory
• Notification of significant process changes
• In addition to unscheduled inspections

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WET Testing Requirements

• Many pretreatment permits issued by
  municipalities to their industrial users now
  include WET monitoring. Such permits usually
  include quarterly testing with increased
  frequency following a failure. A failure is
  defined as a significant lethal or sublethal
  effect at a critical concentration. That critical
  concentration is based on the industrial users
  proportion of the POTWs influent.

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A problem may or may not be obvious -
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Pretreatment TRE Example

• POTW was in violation of its WET limits gtgt gt
  TRE
• In-house processes were reviewed and corrected,
  and toxicity was reduced but not eliminated
• A toxicant identification evaluation (TIE)
  revealed high levels of pesticides in the
  effluent and a pretreatment user review showed
  treatment inefficiencies at a pesticide
  manufacturer.
• The pesticide facility found it had 2 problems

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Example (Cont.)

• 1) dye studies showed a settling pond with 4-7
  days
• retention actually had only 1.5 hours
  retention
• 2) storage barrel rinse was dumped directly to
  the
• retention pond. Pesticide slugs then passed
• through the settling pond to the POTW influent.
• The TRE established two control strategies
• 1) the user dredged its settling pond and
  installed a
• baffling system to increase retention time.
• 2) storage barrel rinse water routed to treatment.

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• Diazinon / Chlorpyrifos - OPs
• POTWs can reduce the risk of toxic discharges
  through active pretreatment and public education
  programs regarding chemical and product use and
  disposal, and by maintaining and maximizing the
  level of wastewater treatment within the design
  limits of the facility.

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Toxicity Reduction Evaluations (TREs)

• Resolution is dependent on magnitude and
  duration
• of toxicity,
• Many facilities have worked aggressively and
• resolved both lethal and sub-lethal toxicity
  issues
• Unresolved toxicity usually related to
  inexperience or
• sloppy work, sampling or lab
• Success is usually a result of good
  communications and
• coordinated efforts between the TRE/WET
  testing
• consultant, the permittee and the permitting
  authority

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Unfortunately, you may not have a lot of highly
qualified scientists or permit writers at your
direct disposal, so lets look at some basics of
WET permitting
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Aspects of Permitting WET

• Application, Fact Sheet, Permit
• WET Monitoring vs Limits
• Monitoring (frequency, species, test)
• Toxicity
• TRE
• Compliance Schedule
• Permit Control

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Assumptions Data gt Fact Sheet Permit

• Receiving Stream Designation
• Aquatic life uses
• Applicable criteria
• Stream and effluent flows
• Application and data quality

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WET Monitoring / Limits Test Type Freshwater/Sa
ltwater Acute /Chronic Species Minnow Daphnids
(Ceriodaphnia dubia, Daphnia pulex) Frequency
Monitoring only 1/Qtr for first year, may
reduce WET limits 1/Qtr, life of permit
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Quarterly Chronic Testing

• For 2 species, costs about 0.35 per month per
  household for a typical 1 MGD facility
• Uses three 24-hour composite samples of effluent
• That is three days out of 90 discharge days
• That is monitoring 3 of the time
• What is happening the other 97 of the time?

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National WET Implementation Guidance Improve
national consistency (w/ flexibility) Public
Review 12/31/2004 03/31/2005 Public
Listening Sessions 90 Sets of comments, 515
pages PERs State NPDES permitting practices
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Major WET Issues for R6

• WET limits based on sub-lethal effects - In 1989,
  R6 did not implement WET limits for sub-lethal
  endpoints due to concerns with technical
  abilities to consistently identify toxicants.
  Since then Region 6 permittees have had the
  option to perform toxicity studies to find
  toxicants. Experience has proven such TREs are
  successful in addressing sub-lethal effects.
• Predictive statistical analysis to determine
  reasonable potential for lethal and sub-lethal
  WET limits

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• Region 6 NPDES Permits
• Toxicity Reduction Evaluations (TREs) and
• WET limits for lethal / sub-lethal effects
• (sub-lethal toxicity threshold 75)
• Return to 3 retests after WET test failure
• 95/95 Predictive reasonable potential
• assessment during permit development
• If CD gt 90 , n gt 10 and no failures in last
• 5 years, reasonable potential default is NO

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Court Challenges on WET

• WET issues have been raised on a national level
  several times and resolved in litigation. EPAs
  WET test methods, and specifically the issues of
  reasonable potential and variability, have
  consistently been upheld by the courts. In a
  unanimous decision rendered by the a panel of 3
  judges from the 5th Circuit of Appeals in
  Washington, D.C., (2005) and sustained by the US
  Supreme Court (06/26/06)

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• Your Best Bet
• Adequate amounts of high-quality data
• Maintain permit limits, BMPs and other
• requirements to preclude additional
• measures.
• Take the initiative, act on results, have
• a plan to deal with the unexpected -

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The largest creature on earth eats only tiny
shrimp but it needs 4,000 lbs of them per day
to survive
Blue Whale
Krill
Daphnids
Bass fry
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ADEQ Narrative Criteria and Definitions

• Aquatic Life
• Reg. 2.409 Toxic Substances - Discharges shall
  not be allowed into any waterbody which, after
  consideration of the zone of initial dilution,
  the mixing zone and critical flow conditions,
  will cause toxicity to human, animal, plant or
  aquatic life or interfere with normal
  propagation, growth, and survival of aquatic
  biota.
• Definitions
• Aquatic biota All those life forms which
  inhabit the aquatic environment.
• Acute toxicity A statistically significant
  difference (at the 95 percent confidence level)
  in
• mortality or immobilization between test
  organisms and a control measured during a
• specified period of time which is normally less
  than 96 hours.
• Chronic Toxicity A statistically significant
  difference (at the 95 percent confidence level)
  in mortality or immobilization, reduced
  reproduction or limited growth between test
  organisms and a control measured during a
  substantial segment of the life span of the test
  organism.

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LDEQ Narrative Criteria and Definitions

• Aquatic Life
• LAC 33IX.1113.B.5. - Toxic Substances. No
  substances shall be present in the waters of the
  state or the sediments underlying said waters in
  quantities that alone or in combination will be
  toxic to human, plant, or animal life or
  significantly increase health risks due to
  exposure to the substances or consumption of
  contaminated fish or other aquatic life. The
  numerical criteria (LAC 33IX.1113.C.6) specify
  allowable concentrations in water for several
  individual toxic substances to provide protection
  from the toxic effects of these substances.
  Requirements for the protection from the toxic
  effects of other toxic substances not included in
  the numerical criteria and required under the
  general criteria are described in LAC 33IX.1121.
• LAC 33IX.1121 - Regulation of Toxic Substances
  Based on the General Criteria
• A.1. The water quality standards in this
  Chapter provide for the protection of human,
  plant, and animal life from the deleterious
  effects of toxic substances. The general criteria
  (LAC 33IX.1113.B.5), in particular, require that
  state waters be free from the effects of toxic
  substances. This requirement is especially
  applicable to those toxic substances for which no
  numerical criteria are established.
• (Cont.)

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LDEQ Narrative Criteria and Definitions (Cont.)

• 2707. Establishing Limitations, Standards, and
  Other Permit Conditions
• 2707.D.1.e. - except as provided in this
  Subparagraph, when the permitting authority
  determines, using the procedures in LAC
  33IX.2707.D.1.b, toxicity testing data, or other
  information, that a discharge causes, has the
  reasonable potential to cause, or contributes to
  an in-stream excursion above a narrative
  criterion within an applicable state water
  quality standard, the permit must contain
  effluent limits for whole effluent toxicity.
  Limits on whole effluent toxicity are not
  necessary where the permitting authority
  demonstrates in the fact sheet or statement of
  basis of the LPDES permit, using the procedures
  in LAC 33IX.2707.D.1.b, that chemical-specific
  limits for the effluent are sufficient to attain
  and maintain applicable numeric and narrative
  state water quality standards
• Definitions
• Acute Toxicity Toxicity that after short-term
  exposure exerts lethal or other deleterious
  impacts on representative, sensitive organisms.
  For whole effluent toxicity testing, it can be
  defined as significantly greater toxicity than
  the control.
• Chronic Toxicity Toxicity which after long-term
  exposure exerts sublethal negative effects, or
  which is lethal to representative, sensitive
  organisms.

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NMED Narrative Criteria and Definitions

• Aquatic Life
• 20.6.4.900 CRITERIA APPLICABLE TO ATTAINABLE OR
  DESIGNATED USES UNLESS OTHERWISE SPECIFIED IN
  20.6.4.97 THROUGH 20.6.4.899 NMAC.
• H. Surface waters of the state with a
  designated, existing or attainable use of aquatic
  life shall be free from any substances at
  concentrations that can impair the community of
  plants and animals in or the ecological integrity
  of surface waters of the state. Except as
  provided in paragraph 6 below, the acute and
  chronic aquatic life criteria set out in
  subsections I and J of this section are
  applicable to this use. In addition, the specific
  criteria for aquatic life subcategories in the
  following paragraphs shall apply to waters
  classified under the respective designations.
• (6) Limited Aquatic Life Criteria shall be
  developed on a segment-specific basis. The acute
  aquatic life criteria of Subsections I and J of
  this section shall apply. Chronic aquatic life
  criteria do not apply unless adopted on a segment
  specific basis.
• (Cont.)

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NMED Narrative Criteria and Definitions (Cont.)

• Definitions
• Aquatic life means any plant or animal life
  that uses surface water as primary habitat for at
  least a portion of its life cycle, but does not
  include avian or mammalian species.
• Chronic toxicity means toxicity involving a
  stimulus that lingers or continues for a
  relatively long period relative to the life span
  of an organism. Chronic effects include, but are
  not limited to, lethality, growth impairment,
  behavioral modifications, disease and reduced
  reproduction.

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TCEQ Criteria and Definitions

• Aquatic Life
• 30TAC Part I 307.6(b) General provisions.
• (1) Water in the state shall not be acutely
  toxic to aquatic life in accordance with 307.8
  of this title.
• (2) Water in the state with designated or
  existing aquatic life uses shall not be
  chronically toxic to aquatic life, in accordance
  with 307.8 of this title.
• 30TAC Part I 307.6(e) Total toxicity
• (1) Total (whole-effluent) toxicity of permitted
  discharges, as determined from biomonitoring of
  effluent samples at appropriate dilutions, will
  be sufficiently controlled to preclude acute
  total toxicity in all water in the state with the
  exception of small zones of initial dilution
  (ZIDs) at discharge points and at extremely low
  streamflow conditions (one-fourth of critical
  low-flow conditions) in accordance with 307.8 of
  this title. Acute total toxicity levels may be
  exceeded in a ZID, but there shall be no
  lethality to aquatic organisms which move through
  a ZID, and the sizes of ZIDs are limited in
  accordance with 307.8 of this title. Chronic
  total toxicity, as determined from biomonitoring
  of effluent samples, will be precluded in all
  water in the state with existing or designated
  aquatic life uses except in mixing zones and at
  flows less than critical low-flows, in accordance
  with 307.8 of this title.

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TCEQ Criteria and Definitions (Cont.)

• 30TAC Part I 307.8
• (a) Low-Flow Conditions
• (2) Numerical acute criteria for toxic
  materials and preclusion of total acute toxicity
  as established in 307.6 of this title are
  applicable at stream flows which are equal to or
  greater than one-fourth of seven-day, two-year
  low-flows (7Q2).
• (b) Mixing Zones
• (2) Numerical acute aquatic life criteria
  for toxic materials and preclusion of total acute
  toxicity as established in 307.6 of this title
  are applicable in mixing zones. Acute criteria
  and acute total toxicity levels may be exceeded
  in small zones of initial dilution (ZIDs) at
  discharge points, but there shall be no lethality
  to aquatic organisms which move through a ZID.
  ZIDs shall not exceed the following sizes

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TCEQ Criteria and Definitions (Cont.)

• Definitions
• Acute Toxicity - Toxicity which exerts a
  stimulus severe enough to rapidly induce an
  effect. The duration of exposure applicable to
  acute toxicity is typically 96 hours or less.
  Tests of total toxicity normally use lethality as
  the measure of acute impacts. (Direct thermal
  impacts are excluded from definitions of
  toxicity.)
• Chronic Toxicity - Toxicity which continues for
  a long-term period after exposure to toxic
  substances. Chronic exposure produces sub-lethal
  effects, such as growth impairment and reduced
  reproductive success, but it may also produce
  lethality. The duration of exposure applicable to
  the most common chronic toxicity test is seven
  days or more.

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ODEQ/OWRB Criteria and Definitions

• Aquatic Life
• 78545-5-12
• (6) Toxic substances (for protection of fish and
  wildlife).
• (A) Surface waters of the state shall not
  exhibit acute toxicity and shall not exhibit
  chronic toxicity outside the chronic regulatory
  mixing zone. Acute test failure and chronic test
  failure shall be used to determine discharger
  compliance with these narrative aquatic life
  toxics criteria. The narrative criterion
  specified in this subparagraph (A) which
  prohibits acute toxicity shall be maintained at
  all times and shall apply to all surface waters
  of the state. The narrative criterion specified
  in this subparagraph (A) which prohibits chronic
  toxicity shall apply at all times outside the
  chronic regulatory mixing zone and within the
  zone of passage to all waters of the state
  except
• (i) When a discharge into surface waters
  designated with the Fish and Wildlife Propagation
  beneficial use complies with and meets the
  discharge permit limitations but the flow
  immediately upstream from the discharge is less
  than one (1) cubic foot per second or when the
  flow falls below the seven-day, two-year
  low-flow, whichever is larger. For purposes of
  the permitting process, the regulatory low flow
  shall be the larger of one (1) cubic foot per
  second or the seven-day, two-year low flow and

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ODEQ/OWRB Criteria and Definitions (Cont.)

• (ii) To streams listed as ephemeral in Appendix
  A.
• Definitions
• "Acute toxicity" means greater than or equal to
  50 lethality to appropriate test organisms in a
  test sample.
• "Chronic toxicity" means a statistically
  significant difference (at the 95 confidence
  level) between longer-term survival and/or
  reproduction or growth of the appropriate test
  organisms in a test sample and a control.
  Teratogenicity and mutagenicity are considered to
  be effects of chronic toxicity.