Part 3 of “Small Towns, Big Pipes,” a series on the infrastructure crisis facing small communities across Illinois.

Nobody thinks about water after it goes down the drain. That is the whole point of a sewer system. It takes the dirtiest part of daily life and makes it invisible.

Until it stops working. Then it becomes the most visible problem a town can have: sewage in a basement, a ditch that smells like an outhouse, a creek nobody will let their kids near. This article is about the systems that carry waste away in small-town Illinois, the towns that never got those systems at all, and why fixing any of it costs more than the towns have.

Two paths for wastewater, both in trouble

When you flush, the water goes one of two places. In towns with sewers, it flows through underground pipes to a treatment plant or lagoon, gets cleaned up and is released to a stream. Outside of town, and in some towns without sewers, each home has its own septic system, a buried tank and drain field that treats waste on the property.

Both approaches work fine when they’re built right and maintained. Both are failing across rural Illinois for the same reason: the money to maintain them ran out a long time ago.

About one in five American households relies on a septic system. The EPA’s own researchers note that septic systems commonly fail from age, poor design, lack of maintenance and root damage, and when they fail, waste can reach streams and wells with little or no treatment. A failed septic tank is not just that homeowner’s problem. It is everyone downstream’s problem.

The 200 towns Illinois never sewered

Here is a fact most people in this state have never heard. The Illinois EPA knows of more than 200 Illinois communities with inadequate or nonexistent wastewater collection and treatment facilities.

Some of these places rely entirely on aging septic tanks that, in the agency’s words, “often provide inadequate treatment leading to illegal surface discharges.” Others have something stranger: what the IEPA calls patchworks of decades-old underground “wildcat” systems. These are pipe networks that residents and contractors cobbled together over generations, with no engineering, no maps and no treatment at the end. The pipe just runs downhill until the waste reaches a ditch or creek. That has been the sanitation plan in some Illinois communities for a hundred years.

Why didn’t these towns just build sewers? Because a collection system and treatment plant for even a tiny community costs millions, and the IEPA is blunt about the barrier: affordability is the biggest hurdle for unsewered communities. There is even a catch built into the main loan program. Engineering costs are loan-eligible, but the money is not released until the loan is issued, which means a struggling town must pay an engineer up front and hope for reimbursement later. Towns that cannot cover a water bill increase cannot front an engineering study.

The state’s answer, and its math problem

To its credit, Illinois built a program for this. Through the Rebuild Illinois capital plan, the IEPA committed $100 million over five years to the Unsewered Communities Construction Grant Program, real grant money, not loans. It pays for design and construction, capped at $5 million per project, with four to ten awards expected each year. A smaller companion program offers planning grants of up to $30,000 so towns can afford the engineering study that the bigger grant requires. The first construction award went to the Village of Alto Pass in southern Illinois, $4.4 million to replace a failing system in a village of a few hundred people.

That is genuinely good policy. Now do the math with us. More than 200 communities need help. The program funds four to ten projects a year. At that pace, the last town on the list gets its sewer somewhere between twenty and fifty years from now, assuming the funding survives every budget cycle in between and assuming construction costs stand still, which they never do. A town at the back of that line has a working sanitation system the same way a person tenth in line for a lifeboat has a seat.

When the sewers you have start failing

Having a sewer system is no guarantee either. Most small-town systems in Illinois were built in one big push decades ago, often with federal grant money that no longer exists in that form, and they have been quietly deteriorating ever since. Cracked clay pipes let groundwater pour in during storms, overloading treatment plants. Pump stations run past their design life. Many small towns treat their waste in lagoon systems, simple ponds that are cheap to run but aging out across rural America.

When an overloaded system lets raw sewage escape, it is called a sanitary sewer overflow, and Illinois has a running case study in what decades of overflows do to a community. In Cahokia Heights, near St. Louis, sewage has been backing into homes and flooding yards for decades. Between 2014 and 2024, that single community accounted for a quarter of all sewer overflow reports filed with the IEPA by smaller, non-permitted systems. Its collection systems, built in the 1980s, were poorly maintained from the start. And reporters found the problem is not confined to one town. An overflow complaint in Johnston City described “dead fish, black water” and “a foul odor” after a break that followed record rainfall.

Rain is the multiplier in all of this. Old sewer systems were sized for the storms of the 1950s and 60s. In the Cahokia Heights region, intense rainfall has increased 25 percent since 1970. Every heavy storm pushes more water into pipes that were too small and too cracked to begin with, and the overflow ends up in basements and creeks.

The size of the hole

The EPA measures the nation’s clean water needs every few years, and the latest Clean Watersheds Needs Survey found the country needs $630 billion over 20 years to meet Clean Water Act goals. Wastewater accounts for $345.7 billion of that, and over 40 percent of the wastewater need is simply pipes and pump stations, the unglamorous buried stuff. Another $74.7 billion is needed for decentralized systems, meaning septic tanks and small cluster systems, exactly the kind rural Illinois depends on. The total need has risen 73 percent since the previous survey a decade earlier. Waiting has not made this cheaper. Waiting is what made it this expensive.

And unlike drinking water, wastewater has no natural constituency. People will show up at a village board meeting about their tap water. Almost nobody shows up about the treatment lagoon. The systems that handle our waste get attention exactly once: after they fail.

What this means here

Every small town in Illinois sits somewhere on this spectrum. Some never got sewers and are waiting in a line 200 communities deep for a grant program that funds a handful of projects a year. Some have sewers older than anyone serving on the village board, quietly cracking underground. All of them face the same arithmetic: systems that cost millions, budgets measured in thousands and a state and federal funding structure that treats sanitation, a basic requirement of public health since the 1800s, as something small towns should borrow their way toward.

Next in this series: the third system, storm drainage, and what happens when hundred-year-old culverts meet twenty-first-century rain.

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