Illinois EPA SWAP Factsheet: What Farmer City’s Wells Show

Reviewed August 2026 against the Illinois EPA Source Water Assessment Program, the U.S. EPA’s national drinking water standards, and Illinois State Water Survey well records.

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Farmer City, Illinois draws its drinking water from four named municipal wells — #11, OlsGold, McConkey, and Luck — completed in the sand-and-gravel formation the Illinois EPA classifies as Aquifer Code 0101. The state’s Source Water Assessment Program (SWAP) factsheet for Farmer City exists and is searchable online, but the Illinois EPA has stripped the well-by-well numbers most searchers actually want — depth, pumpage, exact setback distance — from the public version, and says so on the search page itself. Below is what the factsheet does contain, what Illinois’s aquifer and setback rules require, and exactly which office to call for the numbers that aren’t published.

What Farmer City’s SWAP Factsheet Actually Covers

The Illinois EPA Source Water Assessment Program (SWAP) was created under the 1996 amendments to the federal Safe Drinking Water Act, which required every state to evaluate the areas that feed its public drinking-water supplies. Illinois EPA’s own program page states that SWAP assessments have been completed for approximately 1,700 community water supplies and 3,800 non-community water supplies, together covering more than 12 million Illinois residents — a figure the agency updates as supplies are added, merged, or decommissioned, so the live count on Illinois EPA’s SWAP program page will move over time.

Farmer City’s public water supply — a community groundwater system serving DeWitt County’s Santa Anna Township — is one of those roughly 1,700 community supplies. Each assessment does four things: delineates the source water area around the wells, inventories potential contamination sources inside that area, determines how susceptible the source is to contamination, and reports the findings back to the public. That last step is the factsheet you land on when you search “Illinois EPA SWAP factsheet Farmer City.”

Why the Public Factsheet Hides the Numbers You’re Searching For

This is the part an AI summary won’t tell you, because it requires actually opening the Illinois EPA’s own search tool and reading its fine print. The SWAP Factsheet search portal lets you look up records “by county or public water supply name” — so you can find Farmer City’s entry under DeWitt County without trouble. But the portal itself states that “all locational data and maps pertaining to wells, aquifers and/or surface water intakes have been removed” from the public version, for security reasons. That single sentence explains the whole search behavior behind this page: the factsheet ranks near the top of results for queries like “farmer city aquifer code” and “swap factsheet farmer city well depth aquifer,” people click through expecting a table of numbers, and the document they land on has exactly those numbers stripped out.

Every one of the field names people search for — well ID, well number, well description, status, aquifer code, aquifer description, water system, pumpage, depth, setback — is a real column in the underlying SWAP dataset. They just aren’t rendered on the public-facing summary. Here’s what each term means and whether it survives redaction:

Aquifer Code 0101: What “Sand and Gravel” Means in Illinois

The Illinois State Water Survey (ISWS) maps three major aquifer systems across the state: sand-and-gravel deposits, shallow bedrock, and the deeper Cambrian-Ordovician sandstone system, according to ISWS’s well and groundwater resources page. Code 0101 is Illinois EPA’s classification for the first of those — glacial outwash sand and gravel, the material left behind by retreating ice sheets across central Illinois, including the ground beneath Farmer City.

The classification describes material, not a fixed depth band. A 0101 designation tells you the formation is granular and highly permeable — water moves through it quickly in both directions, which is exactly why these aquifers are productive to drill into and also why surface contaminants can reach them faster than they would through solid bedrock. It does not tell you how deep any specific well was drilled to reach that material; that number is on the same redacted line discussed above. If you need the actual depth for a specific well, the aquifer code alone won’t get you there — you need the well construction report, covered in the “how to get the real numbers” section below.
What that code means on the state’s records, and why it matters for these wells, is unpacked in Farmer City’s aquifer code.

Farmer City’s Water System: Four Wells, One Small Town

What Farmer City does publish, on its own site rather than the state portal, is more useful than most searchers realize. According to the city’s Water & Wastewater page, the community water supply is drawn from four wells named #11, OlsGold, McConkey, and Luck, treated by iron removal filtration and zeolite softening, and stored in a 300,000-gallon elevated tank. The city’s water tower dates to 1920. Annual Consumer Confidence Reports covering calendar years 2021 through 2025 are posted on the same page, and the Water Superintendent, Chad Yeadon, is listed at (309) 928-3412 for direct questions about any of the four wells.

Farmer City sits in DeWitt County and, per the U.S. Census Bureau figures compiled for Farmer City, Illinois, had 1,828 residents at the 2020 census — down from 2,037 in 2010, 2,055 in 2000, and a peak of 2,252 in 1980. That decline matters for reading the factsheet in context: four wells and one 300,000-gallon tank are sized for a system that has been shrinking for four decades, not growing into new demand. The next official update to this figure is the 2030 decennial census; the Census Bureau also publishes annual intercensal estimates in the interim.

Well Setback Zones: The Distances Illinois Actually Regulates

Setback zones are the one number in the search phrases above that Illinois publishes as a flat statewide rule rather than a per-well secret. Under the Illinois Groundwater Protection Act, the statutory minimum setback zone is 200 feet around a private water supply well and 400 feet around a public water supply well, according to Illinois EPA’s Maximum Setback Zones page. Inside that radius, siting new potential contamination sources is restricted by law, independent of which specific well or aquifer code is involved.

A municipality or county can go further by adopting a maximum setback zone — a locally ordinanced buffer of up to 1,000 feet — if pump-test data shows the well’s actual area of influence extends beyond the 200/400-foot statutory minimum. The same Illinois EPA page describes the process: the municipality submits radius-of-influence data, aquifer test results, and a draft ordinance; Illinois EPA confirms the technical adequacy of the method; and the local body then has two years to adopt the ordinance. Whether Farmer City has adopted a maximum setback zone beyond the 400-foot public-well minimum is not stated on the sources checked for this review — that status is confirmed directly with DeWitt County or Illinois EPA’s Groundwater Section, not inferred here.

Setback Zone Distance Checker

Use your own distance from a well to see which Illinois setback tier it falls inside.

Susceptibility and Protection: What the Factsheet Does Tell You

Redaction doesn’t mean the factsheet is empty. The same Illinois EPA search portal confirms that each completed assessment’s public summary covers three sections: “Importance of Source Water,” “Susceptibility to Contamination Determination,” and “Source Water Protection Efforts” documentation and recommendations. The susceptibility section is the closest thing to a risk score the public factsheet contains — it explains how exposed the source is to the contamination inventory Illinois EPA built for that water system, without publishing the well coordinates that inventory is built around.

For Farmer City specifically, the susceptibility rating and the list of inventoried contamination sources are on the record itself — not reproduced here, because doing so from a search snippet rather than the primary document would risk repeating an unverified figure. Pull the current factsheet from the SWAP Factsheet portal under DeWitt County to read Farmer City’s susceptibility determination and protection recommendations directly from the source.

Watch: How a Source Water Assessment Comes Together

For a walkthrough of how states build these assessments from well inventories to public factsheets, see the video below.

Watch this video on YouTube

Federal Benchmarks: Nitrate, Arsenic, and What Counts as a Problem

Whatever numbers do show up on Farmer City’s Consumer Confidence Report, the way to judge them is against the federal Maximum Contaminant Levels (MCLs) set under the Safe Drinking Water Act. Per the U.S. EPA’s National Primary Drinking Water Regulations (last updated December 1, 2025), the MCL for nitrate, measured as nitrogen, is 10 mg/L, and the MCL for arsenic is 0.010 mg/L. Sand-and-gravel aquifers like the one under Farmer City are the formation type where nitrate from surface sources reaches groundwater fastest, which is exactly why the federal nitrate standard is the number to check any reported result against — not a general sense that a level “looks high.”

These two MCLs are set at the federal level and do not change from one water system’s factsheet to the next; they are the fixed yardstick, while the actual measured values in Farmer City’s own water are published annually in its Consumer Confidence Reports, linked from the city’s Water & Wastewater page.

Where Each Factsheet Field Actually Lives

Because no single page answers every part of “Illinois EPA SWAP factsheet Farmer City well depth aquifer,” this table consolidates the actual location of each data point across the four sources checked for this review — a reference an AI summary of any one page can’t assemble on its own.
Well depths and the aquifer code are set out on their own in Farmer City’s well data.

How to Get Farmer City’s Actual Well Depth, Aquifer, and Pumpage Data

This is the durable part of the answer — the redaction policy and the contact points below don’t depend on any single year’s figures, so this checklist should still work whenever you’re reading it:

1. Call the water system operator first. Farmer City’s Water Superintendent, Chad Yeadon, is listed at (309) 928-3412 on the city’s Water & Wastewater page. The operator holds well construction records for #11, OlsGold, McConkey, and Luck and can confirm depth and aquifer detail directly.
2. Contact Illinois EPA’s Bureau of Water, Groundwater Section at (217) 782-1020. This is the office responsible for the SWAP program and the office that can explain what a specific factsheet’s redacted fields would have shown.
3. Request a custom search from the Illinois State Water Survey. ISWS holds more than 370,000 well construction records statewide. Records not yet digitized into the public ILWATER map can be requested by emailing [email protected] or calling (217) 333-9043; be ready to supply the property’s legal description or coordinates.
4. Don’t rely on the Domestic Wells Database for a municipal well. ISWS’s public Domestic Wells Database requires a login request and, by its own description, displays only wells “used for domestic household purposes” — community supply wells like Farmer City’s four are deliberately excluded from that public view.
5. File a Freedom of Information Act request with Illinois EPA for the full source water assessment underlying the factsheet if the office contacts above don’t resolve it. The agency may still withhold precise well coordinates on the same security grounds it cites for the online portal, but the underlying susceptibility narrative and contamination inventory are more complete in the full assessment than in the public summary.

Sand and Gravel Aquifers, Aggregate Mining, and Satellite Mapping

Sand and gravel isn’t only a water source in Illinois — the same glacial outwash deposits classified as Code 0101 are also the state’s largest-volume mined commodity by tonnage, extracted as construction aggregate. Any operator opening a pit in this material faces the same underlying question SWAP asks about drinking-water wells: how deep is the water table, and where does the recharge area sit, before ground is disturbed. That overlap is where remote sensing earns its keep. Farmonaut’s satellite-based mineral detection uses multispectral and radar imagery to characterize near-surface geology and structural features without a drill program, which is useful groundwork before anyone commits to test pits near a mapped recharge zone.

For exploration or aggregate teams scoping a site near a sand-and-gravel system like Farmer City’s, Farmonaut’s mining site mapping tool overlays an area of interest against aquifer and land-use context so proximity to a protected recharge zone is visible before permitting begins. For a fuller technical example of how satellite data translates into a 3D subsurface picture, see this 3D mineral prospectivity mapping sample report. Teams evaluating a specific site can request a custom quote, or contact Farmonaut directly with site coordinates or a KML boundary.

FAQs: Illinois EPA SWAP, Farmer City Wells, and Aquifer Code 0101