Evaluation of Aqueous Parts Washer Waste Waters

PACIFIC NW POLLUTION PREVENTION RESOURCE CENTER
POLLUTION PREVENTION RESEARCH PROJECTS DATABASE

Project Title: Evaluation of Aqueous Washer Waste Waters

Date Last Updated: 10/97

Project Summary:
The aqueous parts wash study consisted of collecting and analyzing effluent samples from parts washing units used by study participants. Wastewater samples were collected from 15 vehicle maintenance and four metal manufacturing facilities during the course of the project. The intent was to collect a sample representative of the wastewater discharged from these units. In most cases, the wastewater was at the operating temperature during the time of collection, ranging from approximately 150 degrees to 195 degrees F.

Wastewater samples were provided to a commercial laboratory for analysis. Each sample was analyzed for the following commonly regulated pollutants: oil and grease; total suspended solids (TSS); and total recoverable cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), molybdenum (Mo) and zinc (Zn). The pH of each sample was also determined in the laboratory and in the field. In cases where laboratory results indicated the wastewater could be a characteristic hazardous waste because of heavy metal toxicity, additional laboratory analyses were requested. These additional analyses were performed after passing the wastewater sample through a toxicity characteristic leaching procedure (TCLP) filter (a 0.6 to 0.8 micron glass filter). The filtered effluent was then analyzed for the metal(s) of concern to assess the effect of wastewater toxicity and metal solubility.

Study results indicate wastewater contaminant concentrations are largely a function of parts washing practices employed by a facility and characteristics of the parts cleaned. In addition, both vehicle maintenance and metal manufacturing facilities have the potential to generate wastewater that is unacceptable for discharge or exhibits the hazardous waste characteristic of toxicity. In general, aqueous parts washers used at vehicle maintenance facilities generate wastewaters with extremely variable contaminant concentrations, often reaching levels that may complicate disposal. Contaminant concentrations in metal manufacturing wastewater samples were generally more consistent and less objectionable.

Project Keywords: aqueous cleaning, parts washer, vehicle maintenance, metal, cadmium, copper, chromium, lead, nickel, molybdenum, zinc

Organization Performing Research: AMPCO Metal Manufacturing Company, Inc.

Primary Research Contact:
Greg Tillison
AMPCO Metal Manufacturing Company, Inc.
5311 West River Road, North
Lorain, OH 44055
phone: (216) 277-1226
fax: (216) 277-9526

Date Research Started/Completed: 12/92 - 9/94

Publications Based on Research: an article on this study was published in the Spring 1997 issue of Pollution Prevention Review, pp. 47-60.

Approximate Project Budget: $700,000

Primary Project Funder: DOE/EE/OIT/Industrial Waste Program

Funder Contact:
Eric Hass (MACTEC)
U.S. Department of Energy
1617 Cole Blvd
Golden, CO 80401
phone: 303-275-4728
fax: 303-275-4788
e-mail: eric_hass@nrel.gov