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Johnson County, Kansas Environmental Department Protecting You and Your Environment |
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1994 Local Limits Evaluation
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The Johnson County Environmental Department and Johnson County Unified Wastewater Districts currently monitor the performance of fourteen wastewater treatment facilities. Six of these facilities receive and process wastewater from industries regulated through the issuance of Industrial Wastewater Discharge Permits. The remaining eight wastewater treatment facilities are recipients of domestic wastewater from residential flows. This study evaluates the necessity of establishing local limits as based upon the effluent discharges and sludge characteristics from the four treatment facilities noted above. Of the remaining two treatment facilities, Indian Creek MSD#1 (Lower Indian Creek) was not evaluated due to the expansion project underway at the onset of this study. The second treatment facility, Mill Creek MSD#1, was not evaluated due to the scheduled completion of the Mill Creek Regional treatment facility in early 1995. The Regional facility will replace Mill Creek MSD#1, along with five other County treatment facilities and the City of Lenexa's wastewater treatment facility. This study will be followed by the 1995 Local Limits Evaluation which will focus on the Indian Creek MSD#1 and the Mill Creek Regional treatment facilities. The 1994 Local Limits Evaluation was conducted in accordance with EPA recommended evaluation guidelines. Treatment facility sampling was initiated in late March of 1994 and completed during June of 1994. Analytical data was assimilated and subjected to evaluation limits established by the EPA, where applicable. Wastewater influent and effluent was sampled from each of the four treatment facilities. Sludge destined for landfill disposal was collected from little Bull Creek SSD#2. Sludge from the Mission Township MSD#1 and Turkey Creek MSD#1 treatment facilities is disposed of through incineration. Ash from the incinerator was analyzed and evaluated against relevant air quality standards. Sludge from Indian Creek Middle Basin MSD#1 is dewatered prior to landfill disposal. The dewatered sludge data, upon conversion, was then evaluated against prescribed sludge limits. Upon completion of the screening evaluations, effluent discharges were found to exceed the EPA evaluation limits for copper, lead, and zinc at Mission Townships MSD#1, Turkey Creek MSD#1, and Indian Creek Middle Basin MSD#1. The wastewater flow to these treatment facilities is primarily from residential neighborhoods. Potable water analysis by Johnson County Water District No. 1 and JCED indicate that these parameters are present in significant quantities in the background water. As such, the exceedances for copper, lead, and zinc were most likely the result of background water. Effluent discharges were found to exceed the evaluation limit for silver at Mission Township MSD#1, Indian Creek Middle Basin MSD#1, and Little Bull Creek SSD#1. Silver discharge control measures incorporated into the recently adopted Johnson County Code of Regulation for Sanitary Sewer Use, 1992 Edition (Article 4, Part C, Section 2, Item J) prohibit the discharge of silver-bearing wastewater from photo-finishing processes not treated with a silver recovery unit prior to discharge into the sanitary sewerage system. The inclusion of this requirement, and subsequent notification of silver dischargers by JCED, should effectively reduce the silver effluent discharges from the treatment facilities. Whereas silver is included in the local limits evaluation as a recommended parameter, no additional regulatory action will be pursued at this time. Little Bull Creek SSD#2 effluent discharge exceeded the cyanide evaluation limit. In response, JCED will conduct a comprehensive cyanide survey of the industries discharging to the treatment facility. Cyanide sources will be identified through industry reporting in reply to the survey. Industrial users contributing cyanide to the sanitary sewerage system will be approached and counseled on cyanide concerns and alternatives. As a result, cyanide levels at Little Bull Creek SSD#2 should diminish to acceptable levels. Cyanide is also a recommended local limits evaluation parameter. Therefore, as with silver, no additional regulatory action will be pursued. Sludge analysis from Little Bull Creek SSD#2 was found to be in compliance with the EPA established evaluations limits. Incinerator ash from Mission Township MSD#1 and Turkey Creek MSD#1 was found to meet applicable air quality limits. And dewatered sludge from Indian Creek Middle Basin MSD#1 was determined to comply with evaluation limits. Based upon the findings in the 1994 Local Limits Evaluation, local limits will not be established for Mission Township MSD#1, Turkey Creek MSD#1, Indian Creek Middle Basin MSD#1, or Little Bull Creek SSD#2. |
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