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Home My WebLink AboutDSHW-1996-004244 - 0901a06880187c78Michael 0. Leavitt Governor Dianne R. Nielson, Ph.D. Execi^ve Director Don A. Ostler, P.E. Director DEPARTMENT OF ENVIRONMENTAL QUALITY DFVISION OF WATER QUAUTY 288 North 1460 West P.O. Box 144870 Salt Uke City, Utah 84114-4870 (801) 538-6146 Voice (801) 538-6016 Fax (801) 536-4414 T.D.D. July 22, 1996 RECEIVED M 2 3 1996 .... ^c?. 03/'/r Oivisfcs of Solid s HaS.ti. te^ J. R. Whimpey, Manager Environmental Services Thiokol Corporation P. O. Box 689 Brigham City, Utah 84302-0689 Dear Mr. Whimpey: Subject: Closure of 9 Septic Tanks; Meeting Between Thiokol and Utah Division of Water Quality (DWQ) on July 2, 1996. Our office has completed a review of Thiokol's proposal to abandon nine industrial wastewater septic tanks by filling them with clean fill dirt and flushing the remaining liquid into the drainfields. AQ analysis results referenced below are the highest levels noted among the nine wells. The review has prompted the following comments: 1) Heavy metal concentrations were extremely high, prompting concern that ground water could be severely impacted by the flushed effluent and by any subsequent leaching of the remaining sludges. Thallium was omitted as an analyte. Although, the possibility of metal immobilization by pH control was discussed in the meeting, much additional information will need to be provided in order for us to seriously consider this possible option. Constituent Arsenic Antimony ~ Barium Cadmium Chromium Copper Lead Silver Zinc Selenium Nickel Analysis Result 400 ug/l 1210 ug/l 17,100 ug/l 4,550 ug/l 9,840 ug/l 199,000 ug/l 26,800 ug/l 2080 ug/l 220,000 ug/l 373 ug/l 18,500 ug/l MCL GW Standard 50 Ug/l 6 ug/l 2,000 ug/l 5 ug/l 100 ug/l 1,300 ug/I 15 ug/l (Action Level) 100 ug/l 5,000 ug/l 50 ug/l 100 ug/l J. R. Whimpey July 22, 1996 Page 2 2) A niimber of volatile orgaitic compounds (VOCs) were detected in various septic tanks at levels exceeding their associated maximum contaminant levels (MCL), i.e: Constituent Analysis Result MCL Benzene 23 ug/l 5 ug/l 1,1-Dichloroethene 35 ug/l 7 ug/l Vinyl Chloride 65 ug/l 2 ug/l Methylene Chloride 13,000 ug/l 5 ug/l (Found in blzmk also) 1,4-Dichlorobenzene 1000 ug/l 75 ug/l Toluene 6,000 ug/l 1,000 ug/l Trichloroethene 42 ug/l 5 ug/l Chlorobenzene 5,100 ug/l 100 ug/l Tetrachloroethene 32 ug/l 5 ug/l 3) One semi-volatile organic compound was detected at a level exceeding the associated maximum contaminant level (MCL), i.e: Constituent Analysis Result MCL bis(2-ethylhexyl)phthalate 8300 ug/l 6 ug/l 4) Some high levels of VOCs were detected (notably methylene chloride), but the associated field blanks for them also showed the same constituents. Given such an occurrence, sampling QA/QC procedures should be used m order that any analyses have valid results. 5) Why were such high detection limits used for VOCs ? For example, benzene has an MCL of .005 mg/l, yet detection limits of .1 to 1.0 mg/l were used. 6) Semi-volatile analyses were done for some septic tanks and not for others. Why the lack of consistency? 7) Some of the analyses were not certified by the lab. 8) The charts showing constituent comparisons utilizing colored lines were too difficult to read (some colors were indeterminant). 9) Septic tank effluent constituent concentrations should be compared to upgradient ground water quality. In summary, current analyses are a matter of concern. The relative difference between the standard and the detected concentration certainly merits further investigation before considering a discharge of the overflow liquids. Additional information should be provided as noted above f f J. R. Whimpey July 22, 1996 Page 3 in order for us to further evaluate your proposal. It is our understanding that you are preparing a more in-depth risk-based assessment than the above proposal encompasses, with comparisons more related to potential effect on ground water than contrast's with background soil levels, etc. This should include the cost-benefit analysis of the different alternatives. We would certainly consider this assessment prior to making a final decision on this matter. In general, your resubmission of additional infonnation should provide us enough documentation to determine the feasibility for additional discharges to previously closed UIC wells and leaving sludges in place to be assessed as SWMU's under the RCRA corrective action. Sincerely, Larry J. Mize, P.E., Manager Ground Water Protection Section LJM:GLJ:wfm cc: Dan Jackson, EPA Region VHI, Denver, CO Bear River District Health Dept. Utah Division of Solid and Hazardous Waste P:\WQ\PBRMrrS\0JACKSON\WP\TH101C0L.SEP FILE:TH10K0L/ UIC