70    CASE STUDY: PROCESS WASTEWATER MINIMIZATION IN
CERAMIC MANUFACTURING BY MANAGEMENT
EFFORTS AND ENGINEERED MODIFICATIONS
Eric Trauner, Project Engineer
James Bilgo, Supervisor of Wastewater Compliance
Kohler Company
Kohler, Wisconsin 53044
INTRODUCTION
Kohler Co. is a manufacturer of plumbing products, small gasoline engines, electrical generators,
fine furniture, and other household goods. Kohler Co.'s largest manufacturing facility is located at
the corporate headquarters in Kohler, Wisconsin, where approximately 5500 people are employed.
Products manufactured at Kohler Co.'s Kohler, Wisconsin plant include small engines and a variety of
plumbing fixtures, including vitreous china toilets and sinks, cast iron enameled sinks and tubs,
electroplated faucets, and assorted plumbing fittings.
This paper focuses on a process wastewater minimization project implemented at the Kohler Co.
Pottery building in Kohler, Wisconsin, where Kohler Co. employs approximately 500 people in the
manufacture of vitreous china plumbing fixtures. The project was part of a larger wastewater minimization and management project implemented at Kohler Co.'s Kohler, Wisconsin site between 1989 and
1993.
The wastewater minimization project at Kohler Co.'s Pottery building incorporated management
efforts and installation of an engineered wastewater recycle system. The completed project ultimately
resulted in a 75% reduction in wastewater discharged from Pottery, from 140,000 gallons per day
(gpd) in 1991 to 31,000 gpd by late 1993.
The purpose of this case study is to describe the following:
1. overall wastewater management and minimization at Kohler Co.;
2. wastewater management and minimization specific to Pottery;
3. Pottery recycle design, construction, and start-up issues; and,
4. key project elements that resulted in such wastewater reductions, and in meeting Kohler
Co.'s Corporate wastewater management goals.
Overall Wastewater Management at Kohler Co.
There are many types of process wastewaters at Kohler Co.'s Kohler, Wisconsin facility, including
wet air scrubbers, water curtain spray booths, electroplating baths and rinses, metal Finishing operations, quench waters (contact cooling water), product testing, wet analytical laboratories, cooling
tower blowdown, and general wash-down waters.
Until the late-1980s, Kohler Co.'s existing sewer system collected several different categorical point
source wastewaters, non-regulated production wastewaters, non-contact cooling water, drinking
fountain discharge, and storm water. Process wastewaters from electroplating were pretreated by
hydroxide precipitation before discharge to the sewer. These combined process wastewaters were
conveyed to two settling lagoons, and clarified wastewater was discharged to the Sheboygan River
under Kohler Co.'s National Pollutant Discharge Elimination System (NPDES) permit. Solids were
dredged from the lagoons every few years and landfilled.
Sanitary wastewater from plant restrooms and showers was collected in a separate sewer system and
discharged to the City of Sheboygan Regional Wastewater Treatment Facilities ("the POTW").
In the late 1980s two significant events occurred which had a direct effect on process wastewater
management at Kohler Co.:
49th Purdue Industrial Waste Conference Proceedings, 1994 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.