vvEPA United States Environmental Protection Agency Office of Solid Waste and Emergency Response DIRECTIVE NUMBER: >502.01(84) IITLt. Permitting of Refinery Oily Wastewater Treatment Ponds APPROVAL DATE: 12-07-34 EFFECTIVE DATE: i2-o?-84 ORIGINATING OFFICE: office of solid waste 0 FINAL D DRAFT STATUS: [ I A- Pending OMB approval B- Pending AA-OSWER approval " [ - ] ^ C- For review &/or comment . . [ ] D- In development or circulating REFERENCE (other documents): headquarters OS WER OS WER OS WER /£ DIRECTIVE DIRECTIVE ------- CORRECTIVE ACTION. DOC: 9502.01(84) Key Words: ' Refinery Wastes Regulations: HSWA §206, 40 CFR 261.21-24 Subject: Permitting of Refinery Oily Wastewater Treatment Ponds Addressee: Robert L. Duprey, Director, Air and Waste Management Division, Region VIII Originator: John H. Skinner, Director, Office of Solid Waste x x. Source Doc: #9502.01(84) Date: - 12-07-84 Summary: Downstream unit sludges from unlined wastewater ponds that treat or store oily wastewaters are similar to those found in the API separator but are not a sufficient basis for defining the material in the downstream units as API Separator Sludge. The Agency is planning to regulate oil/water/solids separation sludges generated in the wastewater treatment system prior to biological treatment There are three ways to regulate these pond sludges: 1) According to HSWA §206, if a refinery pond is releasing hazardous constituents and the refinery seeks a RCRA permit for any unit at that facility, the refinery must undertake corrective action for the releases from the pond. (This could be done through the permit, or pursuant to an interim status compliance order.) 2) The wastes could be regulated as hazardous if they exhibit one or more of the characteristics of hazardous waste (40 CFR 261.21-24). 3) Apply the mixture rule in cases where previously deposited sludge from ., ._ _ a separator is scoured,- resuspended and t-hen carried out of the unit- - with the wastewater. The wastewater becomes a hazardous waste until delisted or discharged to a stream subject to regulation under the Clean Water Act. The mixture rule cannot apply, however, where the API Separator is inefficient and allows sludge to be carried through to a.pond, or where downstream oxidation ponds receive flow that bypassed the API Separator. EPA bears the burden of proof on the demonstration of>the application of the scouring argument. This technically complex argument can be based on established scouring hydrodynamic principles. HQ developed guidance to facilitate the application of the scouring argument. A list of factors was developed to evaluate whether scouring from a given separation occurred. The factors include: o Sludge Accumulation Practices o Separator Effluent o Flow Variability Characteristics o Poor Separator Design or Operations o Sludge Characteristics ------- MEMORANDUM * SOBJECT- Region vin poll- " '' Oily Wastewater T .«.««" ' *. FROMs John H. Skinner. Dt : Office of Solid Waste (WH-562) »«-... TO; Robert L. Duprfey, Director Region 8 - - - Air and Wast2 Management Division (8AW-WM) - i -. ' - - . We have reviewed the proposed Region VIII position discussed in your memo* dated May 1 and October 12. 1934 that ;deflne permitting coverage of refinery wastevater traatjnent ponds. As your staff »ay have informed you, there have been several meetings between ay staff and yours to discuss this problem. We have also net with Chevron. Phillips. Tosco and API anrt, separately, with Rag ion IX to discuss the issue. We share your concern about the throat posed to ground and surface waters by aooe of the unlined wastewater ponds that treat or store oily wastevatera. However, wo believe that the similarity of downstream unit sludges (in terms of lead and chromium levels) to those found in the API Separator are not a sufficient basis for defining the material in the downstream units as API Separator Sludge. In fact, the similarity of these sludges was a significant factor In our decision to nove forward on an . expanded listing to regulate these pond sludges. Specifically, we are planning in a forthcoming listing to e1 oi1/vater/solids separation sludgos generated in the treatment system prior to biological treatment. This listing was originally proposed in Nov»»mb«»r of I9fl0. We expect to issue a notice Identifying all of the available data in support of the listing and to provide sone clarifications in response to previous comments. Current plans are to proaulgata that listing by lato summer. While the listing revision should cov«?r nost sludges generated in these ponds, we realize that does not address your short term problem. He do have some suggestions in this regard. Section 206 of the Hazardous .and Solid Waste Amendments of 1984 provides ------- that persona obtaining RCRA permits must undertake corrective action for all releases of hazardous constituents from any solid waste management unit as a condition of obtaining the RCRA pnrait. Thus, if a refinery pond Is releasing hazardous constituents and the refinery seeks a RCRA permit for any unit at that facility, the refinery would have to undertake corrective action for the releases froa the pond. (This could be done either through the permit, or pursuant to an Interia status compliance order.) This principle applies even 1£ the pond is not considered to hold a hazardous waste, since Section 206 Applies to releases of hazardous constituents from solid waste management units. ..«.., «-<**« A second option for addressing these pond sludges Is to regulate the wastes as hazardous based on their exhibiting one or more of the characteristics of hazardous waste (see 40 CrR f261.21 -24). You mentioned this option In your recent letter with respect to 8P Toxieity. However, your staff seems to have overlooked corroslvity (high pfl has been found in some COO ponds) and reactivity ($261.23(a)(5)). It Is likely that some refinery pond sludges will contain excessive levels of reactive sulfldes. \ The final option that could be used to deal with downstream '- Impoundments and basins is applicability of the mixture rule. It is imperative, however, that your staff understand the proper framework for the application of the mixture rule. To maintain that a pond is regulated because an API Separator is an inherently inefficient unit and allows sludge to bo carried through to a pond, is Inaccurate. Likewise, downstream oxidation ponds are not regulated simply because they aoaetimes receive flow that has bypassed the API Separator. In both cases, the listed API Separator Sludge has not yet been generated. Rather, API Separator Sludge la generated when it is deposited in the bottom of an API Separator. The mixture rule is relevant only in those casos where previously deposited sludge is scoured, reausponded, and then carried out of the unit with the wastawater. If the Region can make a case for scouring from a separator, the mixture rule ia applicable and the wastowater becones a hazardous'wasta until delisted or discharged to a stream subject to regulation under the Clean Water Act. The burden of proof in th« demonstration of scouring ia upon the Agency. Such an argument, although technically complex, can be made based on well established hydrodynamic principles. Realizing that there are limited resources and capability Cor developing such an arqument by the Regions, we have (at the request of your staff) taken an active role in the development of guidance for the application of this argument. Attached to this mereo is a proliminary list of factors that nay be required to establish the occurrence of scouring frora a given separator. These points are being provided at thla time to facilitate the initiation of information gathering in the more serious cases. ------- We hav«> also requested that th« Office of Waato Programs Enforcement (OWP8) develop nor* thorough guidance. That effort is being conducted by their contractor (Metcalf 6 Eddy). We anticipate that your staff will be contacted by then in the near future Ttie> contractor should be able to provide so*e direct assistance to your staff in soara specific cases, thereby serving the dual purpose of training and resolution of specific factors of concern. Nike Barclay (PTS: 475-9727) of OWPE is the Read- quarters lead on that project and should be contacted for any further information. Ben Smith of my staff (PTSi 475-9531) is our technical expert in this natter and the lead on our study of petroleum refineries and their wastes. Do not hesitate to contact hits if additional questions arise pertaining to thla or Bother natters. cc RA'a Region I-X Hike Barclay (OWPE) Stevo Slvernan (OGC) Susan Hanganello (ORC, Region.VIII) ------- Factors To Be Evaluated In Do terra in ing The potential for % * . j Separator Sludge Scouring Sludge Accumulation Practices - Continuous sludge removal"* from tho separator rules out the occurrence of scouring. At the other end of the spectrum are facilities that allow _ sludge to accumulate to considerable depth. Accumulation -".. to a depth greater than 5O% of the flow depth makes scouring ' probable, intermediate ranges of accumulation will prob- ...».., -*, ably depend more heavily on other factors* -" '-- - - ' Variablity - Unless overloaded, units with maximum- to-minimum, flow ratios at tho separator effluent of less than 2 and Inlet flow ratios of less than 4 are probably ^/- not experiencing 'much rosuspension of sludge. . . ?>".. . '-'-.' -.- ' -". "" '* Poor Separator Design or Operation - Factors contributing ;.' to scour conditions include t excessive, inlet or outlet. /.zone turbulence; nominal horizontal velocities greater rr-"than 30 feet per minute; nominal overflow rates (flow/ 7 -surface area) greater. than 10,000 gallons per day/square v foot of basin; basins less than 30 feet in length; opera- &'- t ion 'under pressure (e.g., with a backwater at the' inlet ^ of a separator with a -frozen surface), settling zone ~ turbulence (sometimes seen as bubbling with solids _.'- entrainment) . " '" " '" ' ' \- ',* Separator effluent Characteristics - Excessive weir loadings (e.g., operation with a suppressed weir, flow depth greater than a foot) facilitate carryover of resuspended particles. Visible, large (diameter greater than 1/4 Inch) sludge .'. particles in the separator effluent are strong evidence of scouring associated with microbial degradation of ^ deposited sludge." Sludge Characteristics - Particle size distribution as "/..* measured toy wot sieve and hydrometer analyses is necessary information to define scour conditions. -The presence of -.. coke fines in the wastewater influent is also important because that size of particle «.lmm) is non-cohesive and highly susceptible to rosuspension. ------- |