Iowa Department of Natural Resources
Environmental Services Division

For Immediate Release
April 25, 2007

RAINS OVERWHELM WASTEWATER SYSTEMS ACROSS IOWA

MEDIA CONTACT: Dennis Ostwinkle at (319) 653-2135 or Barb Lynch at
(712) 260-1728.

DES MOINES — Another band of heavy rainfall across the state Tuesday
and Wednesday has resulted in wastewater bypasses.

When wastewater treatment facilities are “bypassed,” sewage is not
treated before it is sent directly into a body of water. Bypasses can
occur as a result of mechanical failures and power outages, but also
from heavy rainfalls or snowmelts.

Heavy rain can overload wastewater collection systems, which are the
underground sewer pipes that carry sewage to a treatment plant. With the
sewage pipes overwhelmed, the excess water has nowhere to go, and can
backup into basements through floor drains. Bypassing can lower the
water level in the collection system, keeping sewage from backing up
into basements, which would present health risks.

“While facilities should not have to bypass, sometimes nature gives
facilities more rain than they can handle,” Barb Lynch, head of the
DNR’s environmental field services.

According to DNR design standards for construction of new wastewater
treatment systems, facilities should be able to handle the amount of
water in the collection system from all three of these events happening
at the same time: *
* Peak sewage flows from homes, businesses and industry
* Peak groundwater levels
* A storm that drops two inches of water in an hour.

While many collection systems in Iowa already have or are in the
process of upgrading their collection systems to handle these events,
many more need to upgrade.

The DNR tracks bypass reports submitted by facilities and follows up
with the facility to determine problems and help them upgrade their
systems, although it can be a long-term process. The DNR has also formed
a committee to discuss how it handles wet weather bypasses.

“Bypasses enter the streams and lakes that Iowans use for fishing,
swimming, boating and for drinking water. Because of this, and for the
fish and plants that live in the water, bypassing needs to be minimized
as much as possible,” said Lynch.

These types of situations can occur when large amounts of rainwater or
snowmelt, also called storm water, enter a sanitary sewer from cracks in
sewer pipes, or improper connections, such as roof drains or sump pumps
hooked up to the sanitary sewer system instead of the storm water
system. The storm water should enter the storm sewer system, which
receives no treatment before entering a stream or lake. Instead, storm
water enters the sanitary sewer system (which treats wastewater from
homes and businesses).

“Communities need to check for sources of storm water getting into
the system, and work with homes and businesses to disconnect storm water
sources from the sanitary sewer, as well as inspecting their sewage
pipes,” said Dennis Ostwinkle, head of the DNR’s Washington field
office and wastewater compliance coordinator.

Facilities are required to report bypasses caused by mechanical
failures to the DNR within 12 hours of onset or discovery. Facilities do
not have to immediately report bypasses from precipitation events, but
must include them in their monthly operating report to the DNR.

The following communities have reported bypasses to the DNR:

Audubon County:
Audubon: The City of Audubon began bypassing wastewater to an unnamed
tributary of Bluegrass Creek at 6 p.m. Tuesday. The city estimates it
will bypass until Friday or Saturday, bypassing a total of 432,000
gallons of wastewater by Friday. The city plans to do test this summer
to locate improper connections to the sanitary sewer.

Black Hawk County
Cedar Falls: The City of Cedar Falls is bypassing 500 gallons of
wastewater per minute from its wastewater plant detention basin to the
Cedar River. The bypass began Wednesday at 3 p.m. and is expected to end
Thursday. Heavy rainfall has caused overflow of the city’s 5 million
gallon detention basin.

Cass County
Cumberland: The City of Cumberland is bypassing wastewater from a lift
station to Seven Mile Creek following heavy rains. The bypass began at 1
a.m. Wednesday and is bypassing at a rate of 100,000 gallons per day.

Crawford County
Westside: The City of Westside began bypassing to East Boyer Creek at
8:30 a.m. Wednesday. The city estimates it will bypass 100,000 gallons
of wastewater by Friday morning. The city conducted smoke testing last
week to locate improper connections to the sanitary sewer.

Dallas County
Minburn: The City of Minburn began bypassing from its lagoon control
structures to an unnamed tributary of the North Raccoon River Wednesday
and plans to continue bypassing due to continued rainfall.

Franklin County
Hampton: The City of Hampton is bypassing partially treated wastewater
to Squaw Creek. The bypass began at 3:30 p.m. Tuesday and is discharging
at a rate of 200-300 gallons per minute.

Grundy County
Grundy Center: The City of Grundy Center began bypassing from its flow
equalization basin to Black Hawk Creek at 2 p.m. Wednesday and will stop
bypassing when conditions allow.

Wellsburg: The City of Wellsburg began bypassing at midnight Wednesday
to prevent wastewater from backing up into basements. As of Wednesday
morning, the city had intermittently bypassed about 144,000 gallons of
wastewater to an unnamed tributary to South Beaver Creek.

Guthrie County
Panora: The City of Panora began bypassing partially treated wastewater
at 10 a.m. Wednesday to the Middle Raccoon River and expects to bypass
1.5 million gallons by Friday. The city is planning on installing new
sanitary sewer lines this summer.

Stuart: Heavy rainfall overwhelmed the Stuart Wastewater Treatment
Facility, leading the city to bypass an estimated 34,000 gallons of
wastewater to Longbranch Creek from 5 p.m. Tuesday to noon Wednesday.
The City of Stuart has taken actions such as sealing collection lines
and eliminating improper connections of roof drains and sump pumps to
the sanitary sewer system, and is preparing to construct additional
improvements at the wastewater treatment plant to reduce the amount of
wet-weather bypassing.

Hamilton County
Blairsburg: Wastewater is overflowing from a lift station along Highway
69 to a ditch. The City of Blairsburg began bypassing sometime after
noon on Tuesday.

Jefferson County
Fairfield: The City of Fairfield began bypassing at 11 p.m. Tuesday to
a tributary of Big Cedar Creek. The city estimates it has bypassed about
185,000 gallons so far.

Keokuk County
Sigourney: The City of Sigourney bypassed about 60,000 gallons to an
unnamed creek, a tributary of Bridge Creek, after a fuse blew on pump
controls at a lift station. The city discovered the problem at 1:30 a.m.
Wednesday and has replaced the fuse.

Marion County
Knoxville: The City of Knoxville is bypassing from its storm water
equalization lagoon to Competine Creek.

Polk County
Des Moines International Airport: The airport began bypassing from its
storm water containment areas to Middle Creek and Yeader Creek at 11:30
a.m. Wednesday, and will continue until the rain stops.

Scott County
Davenport: The City of Davenport discovered a bypass at 12:30 p.m.
Wednesday when a bar screen building lost power and sent untreated
sewage into a drainage ditch which runs to a backwater of the
Mississippi River. The bypass ended at 1:15 p.m.

Van Buren County
Milton: The City of Milton bypassed about 5,000 gallons of wastewater
to a tributary of the Little Fox River from 10 a.m. to 1:30 p.m.
Wednesday.

Webster County
Fort Dodge: After receiving heavy rainfall Tuesday morning, the City of
Fort Dodge began bypassing to a stormwater pond at 8:30 a.m. Tuesday,
and then to the Des Moines River beginning at 1:10 p.m. Tuesday. Due to
additional rainfall, the city reports it will cease the bypass when
weather conditions allow.

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