Section 10. PLATING WASTES
WASTEWATER TREATMENT FOR A SMALL CHROME
PLATING SHOP: A CASE HISTORY
Joseph G. Rabosky, Consulting Engineer
Coraopolis, Pennsylvania 15108
Timothy Altares, Jr., Plant Manager
Paul's Chrome Plating, Inc.
Mars, Pennsylvania 16046
INTRODUCTION
Paul's Chrome Plating, Inc., is a small chrome plating shop located south of the small town of
Mars in western Pennsylvania. The shop specializes in reconditioning and plating small parts of
motorcycles, specialty automobile parts, and other miscellaneous metallic items.
The shop opened for business during the winter of 1978 and was cited for operating without a
discharge permit one month later. Determining the proper design approach for wastewater treatment
required consideration of both economic and technical assessments. Economic considerations were
necessary because the business was new and the owner deeply in debt. A technical assessment was
required because: (1) the owner had limited knowledge of wastewater treatment practices; (2) the
wastewaters contained many of the contaminants characteristic of chrome plating operations; and (3)
the system design constraints required minimization of both treatment time and frequency.
Originally, the shop involved three people; however, employed personnel now number about fifteen to twenty because business activities have substantially increased. These employees perform tasks
both directly involved in the production operations; e.g., buffing, grinding, and electroplating, and in
support functions such as secretarial and bookkeeping.
Normal daily production operations involve crude cleaning of parts with a water spray, immersion
of these parts into acid followed by alkaline solutions, and then electroplating by parts immersion into
copper, nickel, and chromium solutions to provide the desired metallic coating. Each cleaning or
coating operation is followed by parts immersion into a rinse tank to remove localized quantities of
chemical solutions. The tanks containing the concentrated plating solutions are never dumped;
therefore, treatment of only dilute aqueous wastes is required.
All sanitary, drinking, and industrial water at the facility is obtained from an on-site well. Sanitary
sewage is collected and treated in a septic tank. The area of the shop in which nonsanitary aqueous
wastes are produced is the cleaning and electrolytic plating section which is segregated into two
lines—chrome/nickel and copper.
DESCRIPTION OF ORIGINAL OPERATION
The wastewaters generated by each plating line were segregated because their respective tanks were
set in concrete pits. Therefore, all overflows, drippings, and rinse waters from each plating line were
collected in their respective concrete pits and were drained individually and combined in a lagoon. The
lagoon effluent was then discharged to Breakneck Creek, which is a tributary of Connoquenessing
Creek. Several miles downstream, Connoquenessing Creek flows into the Ohio River. Figure 1 depicts
the original wastewater generation and flow scheme.
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