Water Treatment Plant Standby Power Upgrade

Oak Creek, WI

The Oak Creek Water and Sewer Utility‘s Water Treatment Plant and Low Lift Pump Station were constructed in the early 1970s. Since that time, the demands to supply quality water to customers in the Oak Creek community have significantly increased. The original generators used to provide standby power were inadequately sized for current needs and required extensive service and maintenance. The equipment also did not meet current emissions standards and mandated guidelines for providing reliable standby power. In an effort to meet the growing demands, both facilities have been expanded. However, the existing standby power and electrical infrastructure was never updated and was still in need of upgrades to facilitate added electrical loads and to accommodate future growth.

Standby Power Upgrade Details

The two existing 75 and 250 kW natural gas generators were replaced with two 1,040 kW natural gas generators, one generator at the plant and the other at the low lift pump station. Existing building spaces were modified to allow the larger sized generators and associated equipment to fit inside existing buildings instead of constructing a new standby power facility. The design allowed for new generators, electrical equipment, heating water boiler, and chemical mixing equipment to be installed and placed in service while the existing systems remained operational.

The plant work also included the replacement of an existing 2,500 KVA pad mounted transformer with new 3,000 KVA transformer, along with addition of 2.4 KV automatic transfer switchgear interfaced with existing 2.4 KV plant distribution switchgear. The pump station work included the addition of a 480 volt, 3000 amp automatic transfer switch interfaced with one of the existing services feeding an existing main-tie-main switchboard, and an existing motor control center was replaced.

To facilitate the tight construction deadline the following electrical equipment was pre-purchased as two separate projects: one for the two 1,040 kW generators and other for one 2.4 KV automatic transfer switchgear, one 480 volt automatic transfer switch, and one motor control center. All work was sequenced to allow the plant and pump station to remain operational at all times without an outage of processing water and distribution to clients.

Awards

ACEC-WI 2014 Engineering Excellence Award in Building/Technology Systems