- change ups
Next CSO Focus On East Side
Combined sewer overflows into the Grand River were drastically reduced with completion of Phase I in 1995, which involved separation and replacement of nearly 95 percent of the combined sewers in a 3-square-mile area on the west side.
That job, estimated between $160 million to $200 million, included construction of the 30.4 million gallon Market Avenue retention basin, 40 miles of storm sewers, 26 miles of sanitary sewers and 37 miles of water mains, as well as two stormwater pumping stations.
Phase I improvements successfully reduced CSO discharges into the Grand River by 96 percent.
“Now we’re chasing around 4 percent of the original CSO overflow,” said Deputy City Manager Eric DeLong. Upon completion of Phase II in 2006, the city will have eliminated 60 percent of the remaining 4 percent overflow. “By the time we’re done we’ll be down to 98.5 percent.”
The remaining 1.5 percent overflow will be eliminated between 2006 and 2019, noted City Engineer Bill Cole Jr.
Phase II will involve about 3.4 square miles on the east side stretching roughly from Ethel Avenue on the east, the Grand River on the west, Oakdale Street on the south and Ann Street on the north.
More specifically, the south portion of the project will run from Fountain Street to Evergreen Street and from the river to Ethel; the central portion runs parallel to the river from Fountain Street to Leonard Street, between the river and Division Avenue; the north portion runs from Leonard on the south to the river on the west and almost over to Diamond Avenue on the east.
Cole said preliminary estimates call for approximately 40 miles of new sewer construction.
Cost of the second leg of the CSO project will be about comparable to the first. Cole estimates CSO improvements will cost about $114 million.
On top of that will be about $76 million in ancillary costs of related improvements that have to be undertaken in the process — the new streets, curbs, gutters, storm drains, sidewalks, plantings, watermains, gas mains, etc. that have to be constructed to replace the old.
The city basically has to reconstruct a good part of the infrastructure on the east side as part of the project, DeLong pointed out, and that represents a “huge” side benefit for residents.
“On the west side we basically ended up rebuilding 3.1 square miles of the city,” he recalled. “That’s about two-thirds the size of Grand Haven that was rebuilt basically from the roots up. That’s an invaluable contribution to the future of the city.”
One of the biggest challenges in undertaking Phase II will be getting underneath U.S. 131, Cole said. Another challenge will be tying in those east side sewers that are already separated but flow into the combined sewer, so they’re technically not separated until a pipe is installed to serve them.
“The challenge there is we have to design this separation program to take advantage of those separated sewers so they can flow into the new separated sewer we’re going to construct,” Cole explained. “On the west side we had some of that but not as much.”
Phase II will address, to some extent, water quality as well as quantity. He said as engineers go through the design phase for Phase II they’ll be looking for areas of detention and trying to tweak the design of the catch basins to improve water quality.
“The other thing we’re going to be looking at is trying to set up this project so that, if not initially, maybe in the future we will be able to capture what we call the ‘first flush.’ That’s really not part of the project scope right now, but as we do this project we want to design it in a way so that if we want to try to improve stormwater quality, we have the ability to do that in the future. That, along with best management practices, are the things we’re trying to focus on in Phase II probably to a higher degree than we did with Phase I.”
A unique aspect of Phase II is the fact that the city is buying Wright Township’s sewer system and eliminating some lagoons in the township that are polluting Sand Creek, DeLong said.
“By eliminating that discharge, we’re eliminating the equivalent of the phosphorous that we’re currently putting into the river through our CSOs. It’s a unique approach. It solves environmental problems basically in two communities.”
The second phase is no less daunting than was the first, but both DeLong and Cole think the city is better prepared this second time around, having gained experience from Phase I that can be applied to Phase II — including a better understanding of how to communicate with residents affected by construction.
“I think we’re more sophisticated about our designs, too,” DeLong said. “I think we’ve really had the advantage of 10 years of evolution of our design thinking and we’ve made significant progress since then. We may end up using some slightly different designs than we used on the west side that might help with things like traffic calming.”
The city will break the whole project into several contracts with specific construction time frames, then schedule business and neighborhood project information meetings as each portion of the project is undertaken over three years.
Bidding is likely to begin in late summer or early fall. The contracts will be spaced out to minimize impact to the traveling public, as well as neighborhood business groups, Cole noted.
“Realistically, you have to expect some traffic congestion,” Cole observed. “There will be detours and alternate routes, and people will have to adjust their habits as we go thorough construction.”
The city received $15 million in grants for construction of the Market Avenue retention basin in Phase I, and will receive some $13 million in state and local grant monies for the second phase on the east side. But, like Phase I, the city will sell municipal bonds to finance the project and the vast majority of the project will be funded by rate payers.
“What we’ve tried to do is time this in a way where the burden on our rate payers will be minimized because we’ve got the debt from the first phase that will be rolling off at a certain period of time in the future, and that’s when a lot of the debt will be ramping up for the second phase,” DeLong explained.
“There will be a bubble here that will be kind of high but then it will kind of moderate and be more or less level again. We’re trying to tie in the increase in the new to the tailing off of the old to have, more or less, level debt service.”He said Grand Rapids is the most aggressive city in the state in terms of eliminating CSO and with Phase II it will maintain that leading position.