Blending: What's Next?
U.S. EPA needs to resolve a number of issues before finalizing its proposed blending policy
Gary B. Cohen and John C. Hall
Originally published in the April 2006 issue of Water Environment and Technology. Download the original article here.

Last May, when Ben Grumbles, assistant administrator for the U.S. Environmental Protection Agency (EPA) Office of Water, let the U.S. Congress know that EPA would not be finalizing its blending policy, it seemed that a national blending policy would never see the light of day. After all, EPA's proposed blending policy had been a lightning rod of controversy, provoking more than 98,000 comments, and two of the main stakeholder groups had seemingly irreconcilable differences.

The National Association of Clean Water Agencies NACWA; Washington, D.C.), an association representing municipal wastewater treatment plants across the country, had taken the position that blending is not a bypass and that, at a minimum, certain municipal blending activities can be undertaken without being subject to the "no feasible alternatives" test or other bypass criteria. The Natural Resources Defense Council (NRDC; New York), in contrast, has been asserting that blending is a bypass and, as such, is illegal unless it meets the bypass criteria.

Although EPA had essentially given up on developing a national blending policy itself, it encouraged NACWA and NRDC to work together. In October, NACWA and NRDC jointly submitted a proposed blending policy, which they urged EPA to adopt as a national policy. With little change, EPA published a third rendition of a national blending policy on Dec. 22 (70 FR 76013). Although this draft policy received a relatively small number of comments compared to the 2003 policy, the scarcity of comments does not reflect he quality of some of the identified issues.

Why the controversy? EPA regional and state approaches to blending have been widely inconsistent, with some declaring blending to be a bypass subject to 40
CFR 122.41(m). If blending were a bypass, then it would be illegal unless it met the bypass criteria, with the most pertinent provision being the no feasible alternatives test. As such, if a feasible alternative exists, blending would be deemed illegal even though the alternative to blending may have higher costs, may not achieve any higher level of compliance with permit limits, and may not even necessarily improve the quality of the effluent discharged.

The new blending policy differs from EPA's prior versions in that it would now declare all blending around secondary treatment units to be a bypass subject to the no feasible alternatives test. Upon first blush, such an approach appears to be inimical to the historical municipal position and, as pointed out by a number of commenters, should require EPA to undertake rulemaking. Putting aside the question of whether the existing bypass regulation, as a matter of law, should be deemed applicable to blending and whether EPA rulemaking is required, the real issue is whether the NACWA-NRDC blending policy provides a workable solution. At this time, many questions remain unanswered.

One question is how "feasible alternatives" would be determined. The policy contains an exhaustive list of items to be included in the municipal comprehensive utility analysis but provides little guidance on the criteria to be used by the permit writer in evaluating the submissions. Is the decision criterion for determining feasibility to be based on an affordability test? If such a test is used, would it be based upon the median household income? A knee of the curve analysis, consistent with the original secondary treatment rule, potentially could be used in conjunction with or in lieu of an afford ability test to balance the costs and benefits in determining feasibility. However, it is unclear what the benefits are when compliance with National Pollutant Discharge Elimination System (NPDES) permit limits - and, therefore, underlying water quality standards - is already being achieved when blending.

These issues should be clarified rather than left to the interpretation of each permit writer. The concern remains that the feasibility test could be used by regions and states purportedly to justify their subjective preference, adding little to rectify the problem of inconsistent standards being imposed across the country.

Another question: Does the policy intend a more restrictive application of effluent limitations to blended than to nonblended effluent? The biochemical oxygen demand (BOD) and total suspended solids TSS) secondary treatment limits are 30-day and 7-day averages and only apply at end-of-pipe. If blending only occurs for a few days, would the blended effluent have to meet a BOD and TSS 30 mg/L standard, a 45 mg/L standard, or some other standard? Moreover, the secondary treatment 85% removal requirement is a 30-day standard. Does the policy envision the need to demonstrate 85% removal on a daily basis when blending?

The policy relies on the NPDES permitting process as the primary means of implementation. To the extent certainty can be provided to a municipality, it is best for the decision to be reflected in the permit. The draft policy language, however, is unclear as to the extent the permit is intended to provide legal protection. Pending completion of the feasible alternatives identified in the permit implementation schedule, is a permittee deemed in compliance or illegally bypassing? If a permittee misses an implementation schedule date, would· this retroactively designate all prior blending activities as illegal?

Moreover, a significant concern is raised for facilities that currently blend. The policy fails to identify whether these facilities are grandfathered pending, at a minimum, permit reissuance. Surely it is not fair for EPA to be reinterpreting its regulations to immediately place municipalities in noncompliance. This concern is exacerbated by the language in the policy that says EPA "will ensure that enforcement actions are taken, where appropriate, against POTW [publicly owned treatment works] treatment plant operators that fail to move forward expeditiously to meet their legal obligations as determined consistent with th[e] policy."

Furthermore, several facilities have undertaken facility wet weather planning pursuant to a court-approved or other settlement agreement. Hopefully, EPA will not be using the policy as a means to disavow itself from such agreements and impose additional requirements.

Some entities are concerned that the policy purports to require 100% biological treatment - which is beyond the statutory authority Congress granted EPA. Although the policy appropriately encourages the use of innovative physical-chemical treatment, such as ballasted flocculation, it gives the impression that peak flows diverted to such units would have to be re-evaluated during the next permit term to determine whether feasible alternatives exist to eliminate any remaining "bypasses."

Recognizing that EPA's Report to Congress on the Impacts and Control of CSOs and SSOs highlighted ballasted flocculation as a treatment process well-suited for wet weather flows, the policy should be clarified to ensure that it does not discourage the use of such technology. Construction of feasible alternatives and their subsequent abandonment would be a gross waste of municipal resources.

Another concern is the scope of the policy. As written, it covers blending with regard to secondary treatment units, but it is unclear what happens if the same biological unit is used for secondary and tertiary treatment. For POTWs diverting around primary or tertiary units, would blending be subject to the bypass regulation? Which standards would apply? Furthermore, the policy raises the concern that EPA is demanding that all flows go through tertiary units. The costs of "supersizing" advanced treatment systems to avoid blending 'would be astronomical. If the blending controversy is to be resolved, it should address all diversions of peak flows, not just those diverted around biological units. Potentially, a more liberal standard would be recognized for nonbiological or advanced wastewater treatment blending events.

A number of issues remain to be worked out before we will know if the policy is, in fact, workable. Absent a viable policy, it would be incumbent upon adversely affected municipalities to seek review of their permits or other EPA-state actions that adversely affect a municipality's blending activities.
Gary B. Cohen and John C. Hall are attorneys with Hall & Associates (Washington, D.C.).
Originally published in the April 2006 issue of Water Environment and Technology. Download the original article here.