This story and others can be found at:
Pollution Prevention Pays!

General Motors of Canada Limited
Process Modification / Automotive


As a responsible corporate citizen, General Motors of Canada (GMCL) is dedicated to practicing effective
prevention of pollution by seeking practical ways to reduce energy and water consumption, and reducing
discharges to air, water and land.


GMCL’s St. Catharines Components Plant manufactures final drive assemblies for the front wheel drive
transmissions. A part within this assembly is the carrier, a hollow structural housing that supports the
differential gears and sun/planetary gear sets. In the manufacturing process both the exterior and interior
surfaces of the carriers are machined extensively. The machining generates metallic burrs that must be
removed, otherwise these burrs could break free inside of the automatic transmission and cause damage.
The deburring process has previously been performed by using an electrochemical deburr. The
electrochemical process generated significant amounts of sludge consisting of iron hydroxide, sodium nitrate
and water. This electrochemical deburr process was replaced with a mechanical deburr process called
“cascade deburr”. By changing processes, the St. Catharines facility eliminated the generation of a significant
toxic waste stream.


Environmental: With the mechanical deburring process, the St. Catharines Component Plant has achieved
the following annual reductions: 100 tonnes of sodium nitrate, 10 tonnes of nitric acid, and 180 tonnes sodium
hydroxide. The Plant also eliminated the need to dispose of 1,000 tonnes of sludge, a waste generated by the
previous process.
Economic: In 1997, GMCL made a capital investment of $1,986,000 US dollars in St. Catharines’ mechanical
deburr process. GMCL has estimated a payback period of 1.6 years for this project.


Ray Spencer, Environmental Activities (Components Plant) Tel: (905)641-6784
General Motors of Canada Limited Fax: (905)641-6898
570 Glendale Avenue E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
St. Catharines, Ontario L2R 7B3



The purpose of this sheet is to give recognition to this specific activity in pollution prevention. Environment Canada does not per se endorse the company.

                       For more information on pollution prevention visit:                       

Last modified on Thursday, 04 September 2014 19:27

About Us

Located in Independence, Iowa, Iowa Engineered Processes Corp (IEPC) is a privately held business, incorporated in 1981.