In addition to the industrial complexes dotting the lakefront, municipal sanitation sites also expel millions of pounds of chemicals and treated wastewater into the Lake Michigan basin every year.

And some Calumet Region and Chicago-area municipalities are allowed to discharge far greater volumes of pollutants into the lake and its waterways than the more criticized industries, an eight-month Times investigation of Lake Michigan pollution shows.

A Times analysis of state and federal regulatory records for municipal sanitary districts in the Lake Michigan basin revealed:

-- Seven local municipal sites are allowed to dump more of some types of chemicals into lake-connected waterways than the BP Whiting Refinery, where industrial pollution limits have been widely criticized.

-- At least six municipal districts from three states have violated wastewater permits in the last five years -- permits that are intended to keep lake water quality intact.

-- Unlike other cities, Chicago does not disinfect all of its wastewater, leaving area waterways and beaches more vulnerable to contamination.

Dumping: What, where

After scathing criticism last year, BP abandoned plans to increase by 54 percent the level of ammonia and by 35 percent the level of suspended solids it would be permitted to dump in the lake each day. The company vowed to abide by its previous permit limits after a firestorm of criticism from environmentalists and political leaders in Illinois.

But sevenmunicipal sites -- including some in Chicago -- are currently allowed to dump more of at least one of the pollutants per month than BP would have been able to under its expanded limits, a Times review of municipal wastewater permits shows.

Of those public facilities, five are part of the Metropolitan Water Reclamation District of Greater Chicago.

In Indiana, the Gary Sanitary District can dump two to three times as much ammonia and suspended solids a month than BP into the Grand Calumet and Little Calumet rivers, which eventually flow into Lake Michigan.

Permits for municipal sites often include seasonal limits of some contaminants. The permit for the Hammond Sanitary District allows the plant to dump 1,200 more pounds of ammonia than BP's expanded limit in the winter, but not in summer months.

Though Chicago's plants do not discharge directly into Lake Michigan on an everyday basis, three dump into a tributary to the lake or the Chicago River. Collectively, they can dump 50 times as many solids and almost 60 times as much ammonia a month than would have been allowed under BP's controversial permit.

Although a massive, decades-long project in the early 1900s reversed the Chicago River to send waste away from the lake, some experts say dumping into the waterway still damages the lake.

"Despite the fact that Chicago Area Waterway System flows most of the time away from Lake Michigan, the two are still connected," according to a 2007 report by the Alliance for the Great Lakes.

The report, "Protecting Public Health, Caring for Chicago's Waters," also stated: "The irony of the Chicago River is that to protect water quality in Lake Michigan, we have chosen to harm the river.

"To protect the lake, we must protect the river."

In a written response to The Times, Chicago General Superintendent Richard Lanyon said BP has a smaller flow of industrial process wastewater, whereas the flow at Chicago's Calumet plant is much larger from more than one million people.

Chicago's Calumet plant dumps into the Little Calumet River. The water quality standards for the lake are more strict than those for the Little Calumet River, Lanyon noted.

"It is reasonable to have more stringent standards for the lake as compared to the river," Lanyon said.

Although not all Chicago facilities drain directly into the lake or river, all of Chicago's facilities discharge into waters deemed "impaired" by the state of Illinois, meaning their quality has been degraded through contamination.

The same is true for Northwest Indiana municipalities, whose receiving waters include the Grand Calumet and Little Calumet rivers and the Indiana Harbor and Ship Canal, all considered impaired by the Indiana Department of Environmental Management.

Who disinfects?

Indiana and Illinois municipal facilities often face common problems, but they address them differently. One example is that while Indiana regulators require disinfection of municipal wastewater discharges, Chicago does not.

Research shows that disinfection, often with chlorine, helps stave off contamination from E. coli and other potentially dangerous bacteria that can threaten human health and shutter beaches.

IDEM requires Hoosier facilities to disinfect during the recreation season from April 1 to Oct. 1. Three sites that dump into the St. Joseph River -- Elkhart, Mishawaka and South Bend -- are appealing requirements to disinfect year-round.

Chicago sanitary sites ceased disinfecting wastewater in the 1980s because chlorination was creating byproducts dangerous to fish and wildlife, according to the June 2005 Chicago River Agenda.

Twenty years later, the city still doesn't disinfect at its three largest facilities. It does disinfect at three of its other sites, based on quality standards for human waste bacteria in those receiving waters.

The district said it does not disinfect at the other four sites, including its big three, because their receiving waters do not have such standards.

In an e-mail response to questions posed by The Times, the district said it has performed a public health study on recreational use of Lake Michigan, which concluded any risks to human health are low.

Additionally, sometimes up to 100 times a year, heavy rain overwhelms the city's systems, causing combined sewer overflows, or CSOs, of unsanitized wastewater into local waterways, the Alliance for the Great Lakes report says.

Though less frequent, the city has minimized the deluge of heavy rains and CSOs by releasing gallons of excess water directly into Lake Michigan, the alliance report says.

Bacteria from the CSOs, including from human waste, can force swimming bans at Lake Michigan beaches, even beyond Illinois.

Disinfecting could help avert some of the problems, the alliance contends. The group has called wastewater that is not disinfected "a public health liability."

"They need to disinfect," said Jonah Smith, sustainable business director for the alliance. "They got away with this for decades."

Even Chicago Mayor Richard Daley pushed the agency to disinfect in his 2005 River Agenda.

According to the agenda, the city "encourages MWRD to implement cost-effective disinfection technologies that improve the recreational potential of the river while limiting negative impacts on the environment."

Building disinfection mechanisms at the district's three biggest sites -- in Chicago, Cicero and Skokie -- would cost an estimated $541 million, with $22 million in operating fees, according to the district.

Who's violating?

Wastewater permit compliance varies among sanitary districts in the region and other Lake Michigan states and cities.

In Chicago, two of the city's seven wastewater treatment sites have violated permit limits in the last five years.

In August 2006, the Illinois Environmental Protection Agency sent a violation notice to the city's Stickney plant in Cicero for an unlawful discharge of 64,000 gallons of wastewater into Addison Creek, a once-impaired waterway.

Officials at the plant blamed the discharge on contractor error and told the IEPA the contractor had been instructed on how to properly divert excess water.

The Chicago-based Calumet plant, which dumps into the Little Calumet River, has faced stiffer infractions from the IEPA.

Since May 2003, the plant has reported to state regulators at least eight sanitary sewer overflows during heavy rains to nearby Stony Creek.

One of the largest overflows was in January 2007, by almost 2 million gallons of water, IEPA records show.

In July 2007, the IEPA sent the Chicago district a notice of intent to sue the district for failing to implement measures to fix the overflows.

In its response to the IEPA, the reclamation district shared some of the blame with the cities of Palos Hills and Hickory Hills, whose sewer systems lead into the district's Palos Hills pump station. The overflows came during intense rains when the two cities' systems were overwhelmed and overflowed sewers near the Palos Hills pump station, the Chicago district reported.

The district has since met with the cities on projects that would help halt the overflows, the district has reported.

Permit compliance has been even rockier for another Little Calumet River discharger, the Gary Sanitary District.

The district, which dumps into the Grand Calumet River, has received at least six IDEM violation notices since 2003.

The violation notices addressed a range of problems, from exceeding limits of E. coli and mercury to failing to maintain its facility.

In recent years, United Water, the Gary district's contract operator, has sent IDEM several reports of incidents stemming from faulty equipment, including breaking the city's limit for suspended solids.

The contractor sent letters to the sanitary district, one in June, citing "constant failures" of the district's sludge equipment, adding "this is becoming very critical."

Nearly a month later, IDEM sent the district a violation letter for the shoddy maintenance and pollutant exceedances.

The Gary district broke its suspended solids limit at least four times after United Water sent its June letter.

A spokesman from United Water did not return a Times phone call seeking more information about the compliance cases.

In Hammond, sanitary treatment has hit a few snags in the last five years as well.

The Hammond Sanitary District, which serves Hammond, Munster, Highland, Griffith and Whiting and dumps into the Grand Calumet and Little Calumet rivers, has had sporadic trouble staying compliant with wastewater permits.

The Hammond facility has received at least two IDEM violation letters in the last five years. IDEM sent one letter in November 2006 for a sewage backup in a Munster resident's basement stemming from a Hammond sanitary line.

The agency followed up with another letter to Hammond four months later for violations of the city's mercury permit limits.

A Hammond sanitary spokesman did not return a Times phone call for more information on any violations.

The East Chicago Sanitary District, which discharges into the Grand Calumet River and the Indiana Harbor and Ship Canal, has recorded a few compliance blips in recent years.

The district received two IDEM violation letters in May 2003 for using improper forms and calculations to report chemical discharges.

In 2006, the district closed out an agreement with IDEM wherein it paid $26,750 for failing several times to properly monitor and report releases of certain materials.

Pete Baranyai, head of East Chicago's wastewater plant, did not want to be interviewed for this story, his colleague Nickie Geros told The Times.

Major cities in Wisconsin appear to have had fewer recent problems remaining compliant.

The Milwaukee Metropolitan Sewerage District has not violated its permit limits in the last five years, said Gail Mills, permit data coordinator for the Wisconsin Department of Natural Resources.

During the same time period, the Green Bay Metropolitan Sewerage District exceeded by less than 1 percent its monthly limit of phosphorus, which if built up in water can grow vegetation that absorbs oxygen and endangers aquatic life.