Pete Gausewitz, PE
CMET Senior Project Manager
Construction of the City of Grand Rapids’ sewer system, dating back to the turn of the 19th century, used many combined sewers, whereby both storm water and sanitary sewage was conveyed in a single collection pipe. During heavy rains and snow melts, flows were discharged into nearby rivers. Peak overflows in the Grand Rapids area reached 12.6 billion gallons in 1965.
In 1989, the City developed a strategy to eliminate combined sewer overflows by 2019. At the time, 640 miles of separate sewers, 81 miles of combined sewers, and 59 sewer overflow locations existed. Phase I implementation began in 1992 on the west side of the City. This phase was completed in 1999. Phase II implementation began in 1999 on the east side of the city and, although most of the work is complete, is still on-going.
Phase I work covered an area of over 3.1 square miles and included construction of nearly 35 miles of storm sewer pipes. Phase I also included the Market Avenue Retention Basin (MARB), a 30.4 million gallon facility for temporary storage; two stormwater pumping stations; and a river crossing. The cost of Phase I work was $160,000,000. At the completion of Phase II work, covering an area of approximately 3.4 square miles, the total cost of the sewer separation project will be approximately $305,000,000. Black & Veatch was hired by the City to design the sewer separation system and provide on-site inspection during construction. Fishbeck, Thompson, Carr & Huber, a subconsultant to Black & Veatch, has assisted in design and inspection work since the beginning of the project.
During the start of design work in the late 1980’s, Black & Veatch hired MTC as a subconsultant to perform geotechnical investigations for the various work segments or contracts. Soil borings began in October 1990 and, by the completion of Phase I, over 750 soil borings had been completed. We have continued that role during Phase II design work and have completed over 325 additional soil borings since the completion of Phase I.
Our Geotechnical Department completed geotechnical reports for each of the contracts. MTC’s engineers completing the work included Melzar Coulter, PE; Todd Munger, PE; Jon O’Brock, PE; Scott Thompson; Aaron Vanderhill, EIT; and Robert Van Dyke, PE. The geotechnical reports provide information to the design team related to subsurface conditions, allowable soil bearing capacities for structures, groundwater levels, earth retention system considerations, excavation slope stability, and pavement section recommendations.
During construction activities of Phase I and Phase II, our Construction Materials Engineering and Testing (CMET) Division provided on-site testing and inspection of construction materials. Brian Bigorowski served as lead technician. Testing and inspection has included providing fabrication inspection of reinforced concrete box culvert and large diameter reinforced concrete pipe; laboratory testing of bedding, backfill, aggregate base materials; density testing of utility backfill, sand subbase and aggregate base; concrete testing of junction chambers, pavement, curb & gutter, sidewalk, and drive approaches; earth retention system monitoring; laboratory testing of PVC solid wall and truss pipe; and hot mix asphalt field and laboratory testing. Some of the concrete and asphalt pavements are permeable to allow infiltration and reduce stormwater runoff.
The City of Grand Rapids has been a leader in the State of Michigan in eliminating combined sewer overflow. The result of these efforts has been a significant reduction (over 99.8 percent) of overflows to date benefiting water quality in our community and the downstream communities all the way to Lake Michigan.