Grand Rapids to reduce energy costs for sewer system
City also ready to change the way it sanitizes customers’ water.
The city of Grand Rapids will spend up to $3.7 million to make energy improvements to its wastewater system and also add a new and less risky method to disinfect drinking water for its customers in four cities, four townships and Ottawa County.
Commissioners agreed last week to commit up to $2.1 million to cut the city’s energy costs at the wastewater treatment plant and administration building, the Market Avenue Retention Basin and pumping station, and the sewer maintenance building.
Unitary controls will be upgraded, a blower will be replaced, a gas infrared heating system will be installed, energy recovery systems will be expanded and reworked, and improvements will be made to better insulate the buildings to conserve energy.
City Engineer Mark De Clercq said the facilities receiving the improvements contain several aged heating, ventilating and cooling systems.
“The equipment identified has reached the end of its useful life service, thus reducing performance efficiency and increasing annual energy costs,” he said.
Commissioners awarded Chevron Energy Services the $1.9 million contract to perform the work with a stipulation that the total cost can’t exceed $2.1 million. The agreement includes a contingency of 5 percent. Revenue for the project will come from the city’s sewer department and its 2012 bonds.
Nearly a year ago, the city hired Chevron Energy Solutions to conduct an energy analysis for the sites receiving the upgrades and the consultant found the city could save nearly $140,000 in energy costs during the first three years after the changes are made. However, if the average energy cost savings remain at $46,600 a year, it will take about 43 years to recoup a $2 million investment.
“It’s going to take a long time to pay off,” said Deputy City Manager Eric DeLong.
Chevron’s charge to audit the facilities, $36,000, is included in the contract’s cost.
“Chevron ES will provide final design engineering, construction, construction administration, inspection, post energy management and guaranteed energy-saving services all inclusive to this construction contract award,” said De Clercq. “It is a different tool in the tool box. All the services are under this company. It’s a turnkey project.”
The city also will spend up to $1.6 million on a new system to use liquid sodium hypochlorite to disinfect drinking water at the Lake Michigan Filtration Plant. The city has been using chlorine as its disinfectant.
“There are considerably less health and safety concerns related to liquid SHC than those related to the gaseous chlorine, which is currently used for disinfection,” said De Clercq. “The project was also designed for compatibility with future on-site generation of SHC at the Lake Michigan Filtration Plant.”
The project involves creating a complete system to store and feed SHC through the disinfection process. Commissioners awarded the contract last week to Grand River Construction Inc., which submitted a bid of $1.04 million. The city’s cost is not to exceed $1.59 million, which includes a 12 percent contingency.
Arcadis, also known as Malcom Pirnie of Michigan, served as the city’s consultant for the project. The firm will handle the pre-construction phase and make the final inspection. Arcadis charged the city $158,343 for its services; that cost is included in the construction contract.
Revenue for the work will come from the city’s water department and its 2009 bonds.
“The water department may be able someday to produce the solution rather than buy it. Right now, it’s cheaper to buy the solution than produce it. But that may change,” said DeLong.
Commissioners also approved lower water charges and higher sewer rates last week for the city’s water and sewer customers. Water revenue to the city’s department will fall by 4.3 percent next year, while sewer revenue will rise by 2.46 percent. The new rates go into effect Jan. 1.