We may not know them, but we are inextricably linked.

As unfamiliar as their names or products may be to people along the southern rim of Lake Michigan, they are our lake brethren.

The facilities listed as lake basin polluters in the data files of the U.S. Environmental Protection Agency are not just buildings.

They are not just small farms or large campuses lassoed by miles of train tracks.

Their histories and hometowns may be different, but like many communities in Northwest Indiana, their foundations are built on the need for water.

The Times spent eight months investigating -- and in some cases visiting -- 68 companies listed as having discharged chemicals into Lake Michigan or the many waterways in the lake's basin in 2005 and 2006. Along the way were companies that, though possibly major contributors to industrial pollution, also are the lifeblood of communities that span four states.

The following are a few of their stories, told not just by company officials but by the workers and those whose homes share space and waterways with the industrial sites:

Georgia-Pacific, Green Bay, Wis.

If you use Angel Soft toilet paper or Sparkle paper towels, there's a good chance they came from the Broadway Street Georgia-Pacific paper mill in Green Bay.

At 5 million square feet, it's the largest of the company's Green Bay sites and home to the world's largest tissue-recycling operation, the company reports.

The plant is the second-largest discharger of industrial chemicals to the lake basin, releasing 953,782 pounds of materials into the Fox River -- a Lake Michigan tributary -- in 2006, EPA data show.

Visitors to the facility's campus are reminded of the Packers pride that so much of the city wears. They drive to the plant's entrance on Lombardi Avenue, named for the football team's famous coach and winner of Super Bowls I and II.

Officials at Georgia-Pacific denied The Times access to the plant, citing a desire to restrict access to its local media.

But in a written statement, the company described its wastewater treatment, which takes place in an on-site plant.

First, solids created by the paper-making process are removed from the water, which is then aerated to treat the biological oxygen demand, or BOD, the oxygen that is used in breaking down the water's organisms.

Generally, the higher the BOD, the more oxygen has been consumed to break down material.

There is a second treatment to eliminate biological solids, then a sludge process removes phosphorus, which, if accumulated over time in water bodies, can spark overwhelming plant growth that consumes the water's oxygen supply and threaten aquatic life.

The company concedes that "nitrates have been reportable" at the plant. According to the EPA, more than 99 percent, or 950,000 pounds, of the plant's 2006 discharges were nitrate compounds, a chemical mix of nitrogen and oxygen.

Exposure to excessive nitrates can have short- and long-term health effects, including shortness of breath, hemorrhaging of the spleen and even death. But most industrial discharges of nitrate compounds in the lake basin aren't in high enough quantities to pose those kinds of health hazards, experts have told The Times.

Officials call the company's compliance record "exemplary," saying its discharges of suspended solids, a silty treatment byproduct, have been below 5 percent of its permitted levels for 10 years.

What's not exemplary is the quality of the water in the Fox River.

For decades, discharges into the Fox from paper mills producing carbonless paper left the river heavily contaminated with PCBs, or polychlorinated biphenyls. PCBs have been linked to human developmental and reproductive problems and possibly cancer, environmental experts say.

Georgia-Pacific is one of six companies charged with funding and designing the river's dredging project, aimed to remove as many of the PCBs as possible.

If Danielle McQuaid had it her way, she might send her dry cleaning bill to Georgia-Pacific or other companies dumping into the Fox and area waterways.

Digging through the closet of her home a couple of blocks from the mill, McQuaid held up what she says was once an expensive white sweater. It's now the dingy shade of cream of potato soup. A year of washing it in Green Bay water has tinged it beige, she said.

McQuaid said she is torn over her feelings about Georgia-Pacific. The company pollutes the water but also provides the city with important jobs, she said. The company reports it provides 2,300 jobs at the Broadway site alone.

"It's a highly recognized company," she said. "People aren't going to complain about it."

Foremost Farms, Chilton, Wis.

The quiet town of Chilton is full of rural farms and not much else.

The town of 1,180 people and its neighboring city, which bears the same name, are so small and familiar that an emergency call operator gives her contact number as "911: just ask for Joyce."

At the intersection of two roads sits a 125-acre cheese manufacturing plant and a white farmhouse with blue awnings.

The plant produces mozzarella, provolone and string cheeses and is one of 18 member sites of Foremost Farms, a dairy cooperative that, by volume, ranks among the top 10 in the world.

The Chilton plant also ranks No. 7 among industrial sites discharging chemicals into the Lake Michigan basin. It released 74,412 pounds of nitrate compounds into an unnamed creek leading to the Manitowoc River in 2006, EPA data show.

Officials from Foremost denied The Times access to the plant's manufacturing and cleaning processes, citing concerns of potential product contamination. However, they allowed access to the wastewater treatment area, including a lagoon in which the plant sends some treated water for use as fertilizer.

The plant sends 200,000 gallons of water to its treatment plant a day, 95 percent of which is treated and released into the thin creek that drains into the Manitowoc. The other 10,000 gallons are sent to a 1-acre lagoon behind the treatment plant, where the light brown wastewater is concentrated into fertilizer and later spread onto local farmland.

The plant also uses an SBR (sequencing batch reactor) process to treat its wastewater. With SBR, wastewater enters a machine in which biological matter filters out the water's contaminants. The cleaned water can then be returned to the lake basin.

Foremost's Chilton site appears on the EPA's Toxics Release Inventory for discharges of nitrate compounds, a byproduct of cleaning the plant's equipment with nitric acid.

Down the road from the plant is Chilton Town Hall, where a sign hangs warning that pregnant women and children younger than 2 should not drink the town's high-nitrate well water.

Testing helps prevent human consumption of high-nitrate water, and the town has given an average of 625 free testing kits to residents in the past five years, Chilton town manager Doug Koffarnus said. Test results vary, depending on the area of town.

North of Foremost, but not along its discharging stream, the water at Dan Hedrich's house contains nitrates at 15 parts per million. Hedrich's neighbor down the street tests at 23 parts per million.

The EPA has set a safe drinking water standard of 10 parts per million.

Hedrich said he believes at least some of the problem could come from Foremost. Nitrates have a high potential to migrate to ground water, according to the EPA.

But the town's nitrate problem likely stems more from manure spreads than just Foremost's discharges, said Duane Schuettpelz, water resources manager for the Wisconsin Department of Natural Resources.

Mike Bonlander, who has lived in Chilton his whole life, is one of Foremost's 52 employees.

"I'm a cheese warrior," Bonlander joked. "That's what they call me."

His battlefield is the process front line, where he does quality checks on milk before it is used to produce cheese.

Brian Mueller worked at the plant between 1987 and 1996, making and packaging cheese and cleaning the equipment.

Mueller said the plant always has been clean -- "sanitation is a big thing" -- but noted that more measures now are in place to better protect the environment.

The company built a wastewater treatment facility in 1997. Before that, Bonlander said, water was dumped into the lagoon untreated.

"Everything's a lot safer," Bonlander said. "It's all treated. The grass is green where it comes out of the other side."

Menominee Paper Co., Menominee, Mich.

Menominee, Mich., is a beach town in industrial clothing.

About 50 miles north of Green Bay, the 5-square-mile area of about 9,000 people is a tale of two cities.

Long home to industry, Menominee is trying to capitalize on tourism along its waterfront. Condominiums and upgrades to a 280-boat slip marina should help, Mayor George Krah said.

Menominee Paper Co. sits at the mouth of the Menominee River, where it empties into the Green Bay.

The company discharged 50,000 pounds of nitrate compounds into the river in 2006, EPA data show. The company denied The Times access to its plant, citing homeland security concerns.

Officials at the plant referred questions to a Cellu-Tissue vice president based in Atlanta, who did not respond to several interview requests from The Times. Cellu-Tissue Holdings Inc. owns six paper mills around the country, including Menominee Paper.

Built in the early 1900s, the plant makes household wax paper and bags, and it became one of the country's first mills to produce recycled liner board, according the company.

Down a winding road from the plant is Menominee's historic waterfront downtown, a short strip of restaurants and shops. In the large empty lot of what was once an old movie theater, the city has plans for new businesses, including a marine supply shop.

According to a lake monitoring assessment from the Great Lakes Commission, the Menominee basin is in a relatively "clean" area of Michigan and Wisconsin, with residents a short drive from pristine forestry and wildlife.

"A high percentage of the local population is found working for these industrial polluters and relies on the industrial presence for their livelihood," the report says.

Shop owner Linda Murto confirmed the report's finding.

"The last thing people want is to lose those (industry) jobs," Murto said.

Murto owns Aurora Books, once an old electric factory that she and her husband converted into a shop to sell new and used books. Her store faces the city's bandshell and is minutes away from the city's industrial waterfront.

Menominee residents are not very aware of any existing water problems, Murto said. The Great Lakes report supported her theory, noting, "little evidence was found pertaining to public awareness ... especially when compared to other basins in the area."

The small city gets its water from Lake Michigan and doesn't have any problems with its quality, Krah said.

Thilmany Papers, Kaukauna, Wis.

The pale pink paper of Sweet'N Low sweetener and the liner in Pringles chips tubes are made at Thilmany Papers in the small city of Kaukauna, Wis.

Kaukauna is home to 14,000 people, nesting spots for bald eagles and the first deeded property in the state of Wisconsin, a white-pillared colonial across the street from Thilmany.

Thilmany, which sits on a kind of island surrounded by the Fox River, released 24,747 pounds of materials into the river in 2006, EPA data show.

The Fox River separates the 1000 Islands Environmental Center and Thilmany, whose towering campus plays backdrop to a habitat for geese and bald eagles.

A sign hanging on a pier over the Fox from the center's back yard reads: "Fish from these waters contain chemicals. Eating too much may be harmful, especially for women and children."

Founded in 1883, Thilmany makes industrial packaging and pressure-sensitive papers, including those used in feminine hygiene products and in wax-based sandwich wraps.

The company denied The Times access to its plant and declined numerous interview requests, calling itself "conservative" in granting media access. A spokeswoman referred questions about its permit and compliance history to Wisconsin regulators.

On one shelf in Kaukauna Mayor Gene Rosin's office sit two manuals that play key roles in his life: a well-worn Cabela's catalog and a large black binder labeled "PCBs."

Though PCB dredging has not taken place in Kaukauna, its stretch of the Fox is impaired with the chemical, much like many others throughout the state, Rosin said.

Thilmany has been a big donor to the nearby environmental center, Rosin said, showing that industry and environment can coexist.

"Thilmany has been an excellent neighbor with the city," Rosin said.

One recent example is a partnership using the company's landfill. Thilmany uses an off-site landfill with large, lined, open-ground cells to store some of its waste, Rosin said.

The city has been able to store materials from demolished buildings at the landfill for later construction use.

Rosin called Thilmany, the city's largest employer, "very important" to the area. Three Thilmany employees serve on the City Council, and 1,200 people work at the plant.

About 40 years ago, Lester Wyngaard joined the Thilmany ranks. Then in his early 20s, he began his career in the company's holiday wrapping paper division.

Wyngaard begrudgingly retired three years ago as head maintenance worker of one of the plant's large production machines. The 63-year-old now cuts grass at one of the city's two golf courses.

Wyngaard said the facility has vastly improved how it treats its wastewater and disposes of it.

The plant is cleaner than in years past, when it discharged untreated water in local waterways, Wyngaard said.