Apr 15, 2009
For nearly a decade, the Metropolitan Water Reclamation District has resisted calls that it disinfect wastewater discharged into the Chicago area waterways system, arguing among other things that it’s too costly.
MWRD’s estimate that disinfection would cost nearly $1 billion over 20 years is widely reported (although as recently as February 23, in a letter to the Tribune, MWRD president Terrence O’Brien claimed a 20-year cost potentially greater than $2 billion).
But a 2006 study commissioned by the US EPA came up with much lower figures.
O’Brien’s $2 billion figure is found in a 2005 cost estimate by MWRD, which concluded that ultraviolet disinfection technology was most cost-effective, and if combined with filtration of suspended solids, it would cost $2.15 billion over 20 years. (That includes capital costs of $1.56 billion and annual operating and maintenance costs of $30.5 million.)
Without filtration, according to that report, ultraviolet disinfection would cost $963 million. Reviewing that report, US EPA consultants studied and rejected the need for filtration.
But the US EPA review also pointed out that MWRD’s estimate for disinfection without filtration ignored cost savings associated with decreased need for pump stations and electrical power, and it included buildings to house ultraviolet units, though these are generally housed (at much lower cost) in covered channels.
Adjusting MWRD’s estimate for disinfection without filtration — $541 million in capital costs and $21.4 million in annual costs — US EPA projected $380 million in capital costs and $13 million in annual costs. That would bring 20-year costs down below $650 million.
It would add less than $25 to the annual property tax bill of area residents, according to US EPA.
The US EPA report also provided cost estimates based of methods used by Indianapolis and by the nonprofit Water Environment Research Foundation. Using the Indianapolis methodology, capital costs were projected at $242 million, and annual operating and maintenance costs at $8 million. By WERF’s methodology, the figures were $118 million and $7 million.
Environmental groups believe MWRD is exaggerating the cost of disinfection as part of a strategy of delaying action, said John Quail of Friends of the Chicago River.
“It’s a false issue,” he added, since under the Clean Water Act the only acceptable cost considerations are those involving “major economic impact,” and these numbers don’t rise to that standard.
“The Clean Water Act requires that if you can clean up a water body, then you must,” said Ann Alexander of the Natural Resources Defense Council. “The question is not whether the District wants to spend the money, it’s whether it needs to spend the money to comply with the law.”
MWRD is also doggedly pursuing scientific studies with the aim of disproving the need for disinfection, Alexander said. A risk assessment by the District has come under heavy criticism by scientists from US EPA and NRDC. While an epidemiological study now being ramped up by MWRD “is better quality science,” it’s not considering potential uses of the waterways, she said — and given the negative bias of such studies, a single study offers “no basis to throw away years of accumulated wisdom about disinfection, and to refuse measures that will protect the public.”
“We have known for more than a century that sewage-related waterborne pathogens are harmful,” she said. “That is why the US EPA has set standards to protect people from them, and why pretty much every other major municipality in the country disinfects its sewage.”
The Illinois Pollution Control Board is expected to rule this year on a recommendation by the Illinois EPA — supported by the Chicago Department of the Environment — to require disinfection. MWRD and IEPA have testified at pollution board hearings, and environmental groups will start presenting experts and arguments today.