Tools and Approaches for NPDES Permit Implementation

of Water Quality Criteria for Toxic Pollutants

Principles

1.  Meet water quality standards and protect beneficial uses wherever attainable.

2.  Approach/tool must be legally defensible.

3.  Approach/tool should provide a long term or permanent fix whenever appropriate.

4.  Favor approaches with multiple benefits.

a.  Often, this will mean favoring source reduction/pollution prevention over treatment.

5.  Be efficient with DEQ resources; use solutions and tools with reasonable/low agency administrative costs.

6.  Prevent situations where high costs/economic harm are imposed that do not result in real/significant environmental gain.

a.  Approach/tool should be practical and produce measurable near-term results.

7.  Absent adequate representative data, DEQ should make reasonably conservative assumptions in favor of meeting standards and protecting uses.

a.  Sources and the agency are jointly responsible for ambient data.

b.  Sources are responsible for effluent and influent data.

c.  Data collection should not be postponed.

8.  Each source should be responsible for their contribution, but it may not need to be treatment.

9.  Understand whether a solution creates inequities among like facilities across the state.

10.  Solutions should allow site specific flexibility.

11.  Look ‘upstream’ as much as possible. (i.e. often source reduction preferable to treatment)

Problem Statements

1.  Some criteria will be below detection or quantitation limits.

2.  Municipalities may take in pollutants in source waters, which could be a mix of ground water and surface water sources; from conveyance piping (i.e. copper, others?); from inflow and infiltration of groundwater into piping (i.e. arsenic, others?).

3.  For some pollutants, no feasible treatment technology is available that will reliably treat to required levels, either because:

a.  The technology does not exist or is unproven that will perform to the required level for wastewater, or

b.  The technology is prohibitively expensive.

4.  Clean-up site discharges, in some cases, can not treat to the detection limit, particularly if detection limit is reduced (e.g. DDT detection limit is changing from 0.1 to 0.01 µg/l)

5.  In some places, standards may be incorrect (use or criteria).

6.  Limited data results in high levels of uncertainty for doing reasonable potential analysis and setting permit effluent limits. Higher uncertainty can lead to more stringent limits.

Desired Outcomes

1.  Do not create adverse environmental impacts.

2.  Do not adopt regulations that effectively require cost prohibitive treatment if other solutions are available that can provide equal or better environmental results.

3.  Develop policy/guidance on appropriate application of the methylmercury fish tissue criterion. Determine whether alternatives to WWT, such as Hg source reduction measures, may be applied rather than WQBELs.

4.  Sources should be responsible for providing data on their intake water and for characterizing the ambient water quality in the vicinity of their discharge for use in reasonable potential and mixing zone analyses.

5.  Sources should reduce/treat to the levels they can. At the same time sources should not be required to treat for those pollutants levels they can not achieve.

6.  Solutions should be as efficient as possible, not administratively onerous.

Approaches and Tools for Implementing Toxics Criteria in NPDES Permits

Some of these tools may work in combination with each other as shown in the table below.

1. Permit compliance based on the quantitation limit (QL)

Although WQBELs must be based on the criteria and are calculated, if they are below the QL for the pollutant, the compliance point for discharge monitoring and reporting is the QL, the minimum level that is measurable. This is current DEQ policy, as described in DEQ’s Reasonable Potential Analysis Internal Management Directive (RPA IMD).

Recommendation: No new rule language needed.

2. Compliance schedules

This is an existing tool that provides time for a facility to put into place treatment technologies and/or other controls in order to attain an effluent limit in a defined period of time, generally not to exceed the 5-year permit term.

Recommendation: Propose rule language that authorized compliance schedule specific to human health criteria so that it may be approved by EPA and become effective without waiting for formal ESA consultation.

3. Source reduction

Source reduction refers to a variety of ways a facility could reduce the amount of a pollutant that enters its waste stream (removing it at the source) and therefore reduces the amount that would have to be removed from the wastewater through treatment prior to discharge. Examples include: drug or mercury take back programs, household hazardous waste collection events, silver recovery technologies at dentist offices or photo labs, product bans, regulations on the disposal of certain wastes into a POTW, and other alternatives to disposal of specified wastes into the POTW from households or small businesses. In addition, industry may conduct source reduction programs by substituting raw materials, improving processes so that use of materials is more efficient and waste volume is reduced, or reusing/recycling materials on-site.

Source reduction options are allowed and encouraged under existing policy. In some cases, although source reduction will allow a permittee to meet a WQBEL, a compliance schedule may be needed to allow the facility time to put programs in place and attain the needed load reductions in their effluent.

If there is uncertainty about whether the proposed measure will attain the results required to meet an effluent limit within a specified time period, the source may wish to request a variance until the measures/system is tested and proven effective.

Recommendation: A compliance schedule rule and variance rule revisions should be adopted and applied where appropriate to encourage innovation and expanded use of source reduction options. Generally, source reductions options also have the benefit of reduced potential for accidental release of toxic chemicals to the environment, reduced risk of worker exposure and reduced use of material and/or energy to treat the effluent and dispose of any toxic solids that are removed.

4. Pollutant Trading

For the purpose of this discussion, DEQ will define trading as occurring when a source reduces the load of a pollutant outside their facility in order to reduce the upstream ambient concentration and create assimilative capacity for their discharge. Under this scenario, permit limits based on meeting the criteria in the receiving stream at the edge of any assigned mixing zone or another designated compliance point can be met. New rule language is not required in order for DEQ to allow this type of trading. However, the source may need to have a compliance schedule to provide the time for the proposed action to be implemented.

Recommendation: Adopt a compliance schedule rule for human health criteria, which will allow time for trading to occur and criteria to be met.

5. Offsets

For the purpose of this discussion, DEQ will define an offset as occurring when a discharger reduces the load of a pollutant from another source, off site, in order to mitigate their pollutant load. In this case, a portion of the water body at the point of discharge will not meet water quality criteria. Therefore, a variance may be required to allow this approach to occur. An offset is a means by which a source can be responsible for their pollutant loading even if they can not meet the criteria. It may also be a means by which a source can achieve pollution reductions in a more cost effective manner than end of pipe treatment.

Recommendation: Adopt revised variance rule language and develop an implementation document to describe how offsets would occur, under what conditions they would be allowed and what requirements would apply.

6. Intake credits

This would be modeled after the Great Lakes Initiative intake credit, or that of another state, which has been approved by EPA. This type of intake credit allows no increase in either the mass or concentration of the pollutant. It is simply for the pass through of pollutants in the intake water. DEQ does not expect that this provision will be a solution in very many cases in Oregon, but it would be useful to have in the “tool box” in case there is a circumstance for which it is well suited.

Recommendation: Propose an intake credit rule.

7. Variances: streamlined individual, multiple discharger and/or water body

Please see the separate documents provided on variances and how they have been used in other states. DEQ currently has a variance authorizing rule but no variances have been issued in Oregon. Part of the purpose of the rule revisions would be to make this a more viable tool where appropriate.

Recommendation: Propose revisions to the variance rule.

8. Watershed or “bubble” permit

More research is needed on this topic to understand how it would work relative to human health criteria.

Approaches That Are Not a Priority for Further Development at This Time

1. WQ benchmarks, phased implementation, similar to Phase 1 stormwater permits

This was from FIIAC matrix.

2. Sources could pool resources to obtain better ambient data (i.e. from 3^rd parties such as USGS). This could help provide more certainty in conducting reasonable potential analyses and calculating effluent limits.

3. Set site specific criteria and/or conduct UAA to remove beneficial uses where standards are incorrect. There may be waters of the state that are inappropriately designated for domestic water supply use, for example, some irrigation ditches. If DEQ removed domestic water supply as a designated use, the water + organism criteria would not apply to that water body.

4. Intake concentration allowance.

DEQ is distinguishing an intake concentration allowance from an intake credit in that this provision would allow an increase in the concentration of the pollutant in the effluent above the intake water as long as there was no increase in mass loading.

Information on intake credits and a possible intake concentration allowance (de minimis increase) has been provided and discussed at prior meetings. These will be re-visited following RWG discussion of other tools.

5. Dynamic permits (i.e. flow based)

In this case, the dilution provided by the receiving water is tiered based on streamflow rather than assuming that the streamflow is always at the 7Q10 low flow. The source would be required to meet the criteria when flows are at the 7Q10 level, but when they are higher, some relief is provided.

6. Pretreatment for sources discharging to POTWs

Select sources are required to treat their waste before discharging it to a POTW.

- Should additional pretreatment requirements be considered for sources discharging pollutants to a POTW if the POTW has a reasonable potential to exceed a HHC?

- Should there be a DEQ rule on this or should that be up to the POTW/city?

7. Apply high-tech (i.e. Reverse Osmosis) treatment to a concentrated portion of the wastewater where that is more practical or economical than treating the full discharge volume.

-  Can someone provide an example of how this might work?

-  How is this different from “pretreatment”?

8. Review 303 listing segments relative to the implications for mixing zones.

This issue was removed from above because DEQ is already working to correct it and this issue is not part of the permitting program.

Problem statement: WQL listings may not be accurate for a specific location, for example, because the geographic scope of the listing extends beyond the data locations. This may lead DEQ to unnecessarily prohibit the use of a mixing zone. If a stream is listed as WQL, mixing zones are not allowed for the listed pollutant.

Desires outcome: Do not overextend 303d listings to stream reaches that are not actually impaired if this will unnecessarily prohibit a mixing zones that would otherwise be legal and will not impair beneficial uses.

Approach: Ensure 303d listings are correct and properly “segmented” so mixing zones are not unnecessarily prohibited.

Note: Permit compliance is generally measured in effluent at the point of discharge (end of pipe) using specified quantitation limits.