Live Threats Watchlist

Why this matters: The legal framework in Wisconsin is stable. The facts on the ground are not. These 8 items are the ones that could change what a parcel is worth, what you can build on it, or whether the water coming out of the tap is safe.

Every item is dated. Re-check anything older than 6 months before you rely on it. Facts current as of July 2026.

---

1. Data center water and power demand, southeast Wisconsin

What it is. A hyperscale AI buildout across Racine, Ozaukee, Dodge, and Kenosha counties, on a scale Wisconsin has not seen before. Four projects, roughly 4.5 gigawatts of combined announced power demand.

Why it matters to a landowner. Three separate channels.

Water: the projected consumption from closed-loop cooling is genuinely small compared to municipal or agricultural use. The real uncertainty is the gap between contracted capacity and projected use. Meta contracted for 50 million gallons per year while projecting under 8,000 gpd. Vantage’s city agreement allows up to 1.2 mgd against a 22,000 gpd projection. Contracted capacity is a claim on the municipal system, and a municipal well drawing that volume affects the regional aquiferaquiferUnderground rock or sand with water in the spaces between the grains. It is not an underground lake. Water seeps through it slowly, often only feet per year. whether or not the contract is fully exercised.

Power: this is the larger near-term pocketbook issue. Vantage requested 1.3 GW. Microsoft expects around 2 GW at Mount Pleasant full buildout. ATC has proposed a $1.4 billion transmission project. On April 24, 2026, the Public Service Commission of Wisconsin approved a special electric rate for customers requiring 100 MW or more, requiring those customers to pay the full cost of the added generation and transmission serving them, including 2 proposed natural gas plants. Commissioner Kristy Nieto: “Existing Wisconsin customers should not pay a single cent to subsidize the service of data centers or very large customers.” Whether that holds in practice is the thing to watch.

Land: 1,900 acres bought by Microsoft in Racine County, 2,000 acres assembled in Port Washington, 800 acres in Beaver Dam. Rural land values within commuting distance of these sites have a new floor and a new buyer of last resort.

CompactcompactA binding agreement between states that Congress approves. Once approved it becomes federal law and overrides conflicting state rules. The Great Lakes Compact is one. angle. None of these trigger CompactcompactA binding agreement between states that Congress approves. Once approved it becomes federal law and overrides conflicting state rules. The Great Lakes Compact is one. review. Mount Pleasant is a straddling communitystraddling communityA town sitting partly inside and partly outside the Great Lakes basin. It can apply to divert water with its own state's approval., so Racine can serve it inside its existing 7 mgd approval with no Council vote. Port Washington and Beaver Dam are in-basin. The 5 mgd consumptive useconsumptive useWater that is taken and never comes back: evaporated, transpired by plants, or built into a product. This is the number that actually matters. threshold for regional review is far above any of these projections. See Great Lakes Compact, section 7a.

Transparency problem. Midwest Environmental Advocates has had to sue for basic figures. The City of Racine released Microsoft’s water projections only after litigation over a records request. The PSC denied MEA’s request for Meta’s unredacted Beaver Dam power request on trade secret grounds, and MEA filed suit in Dane County Circuit Court on December 9, 2025. Assume any publicly stated number is a floor.

What to monitor.

• MEA data center transparency docket
• PSC of Wisconsin dockets for ATC transmission and the large-load rate class
• DNR Water Quantity Data Viewer for new high capacity wellhigh capacity wellIn Wisconsin, a well (or all wells on 1 property combined) capable of pumping 100,000 gallons a day or more. These need DNR approval. An ordinary house well does not. approvals near these sites
• Municipal water and wastewater agreements, obtainable by open records request from the city clerk
• Whether the Regional Body acts on IJC Recommendation 14 (data center best practices and cumulative impact modeling)

Sources: Microsoft, June 23, 2026; WPR on Mount Pleasant expansion; WPR on Port Washington; Vantage Lighthouse FAQ; City of Kenosha data center FAQ.

---

2. PFAS

What it is. Per- and polyfluoroalkyl substances, a family of synthetic fluorinated chemicals used in firefighting foam, non-stick coatings, and paper coatings. They do not meaningfully break down and they move readily in groundwater.

The regulatory picture

The gap that matters: about a third of Wisconsinites drink from private wells, and there is no enforceable state groundwater standard for PFASPFASThe "forever chemicals" from firefighting foam and industrial processes. They do not break down, treatment is expensive and permanent, and standards keep tightening. Never in a standard water test unless you ask for it by name.. If you are buying a property on a private well, nobody is testing it but you.

Sources: CR 25-068 rule text; Midwest Environmental Advocates, PFAS regulations; DNR draft groundwater rule DG-02-25.

Wisconsin Manufacturers & Commerce v. DNR, 2025 WI 26

Decided June 24, 2025, 5 to 2. Protasiewicz, J. wrote the majority, joined by Ann Walsh Bradley, C.J., Dallet, J., Hagedorn, J., and Karofsky, J. Hagedorn, J. also filed a concurrence. Rebecca Grassl Bradley, J. dissented, joined by Ziegler, J.

The question: must DNR promulgate rules identifying every substance, with quantity and concentration, that qualifies as a “hazardous substance” under Wis. Stat. 292.01(5) before the Spills Law applies to it? Specifically, must DNR name PFASPFASThe "forever chemicals" from firefighting foam and industrial processes. They do not break down, treatment is expensive and permanent, and standards keep tightening. Never in a standard water test unless you ask for it by name. by rule before requiring reporting and cleanup?

The court said no, and reversed the court of appeals. Holdings:

1. DNR’s website statements and letters identifying PFAS as hazardous substances were guidance documents, not unpromulgated rules. Wis. Stat. 227.10(1) does not apply to guidance documents.
2. DNR’s interim policy of offering only partial liability exemptions in the Voluntary Party Liability Exemption program was also a guidance document.
3. DNR has “broad but explicit authority” under the Spills Law to enforce a reporting threshold for hazardous substance discharges without promulgating that threshold as a rule. This satisfies Wis. Stat. 227.10(2m).

Note the caveat in the opinion: DNR cannot cite those guidance statements as legal authority in an enforcement action. The force comes from the statute’s own broad definition of “hazardous substance,” and each substance must still satisfy the fact-specific criteria in 292.01(5).

Why it matters to a landowner. The Spills Law, Wis. Stat. 292.11(2) and (3), imposes duties on a “responsible party,” which includes a person who possesses or controls a hazardous substance or causes a discharge. That can include a property owner who did not create the contamination. WMC keeps PFAS squarely inside that framework. Buying a parcel with a PFAS plume can carry reporting and remediation exposure. Environmental due diligence and a Phase IPhase I ESAAn environmental background check on a property's history. Standard for acreage, and it establishes a legal defense if contamination turns up later. are not optional on any parcel with an industrial, airport, fire training, or biosolids history.

Sources: Full opinion; Justia; WisBar summary.

Marinette and Peshtigo (Tyco / Johnson Controls)

The largest PFAS site in the state, from decades of firefighting foam testing at Tyco’s Fire Technology Center.

Sampling shows 236 of 776 wells tested by Tyco or DNR exceed state health advisory levels for PFAS in groundwater.

The unresolved piece: under the settlement, DNR will not require Tyco to further investigate or clean up the Expanded Site Investigation Area. Tyco has refused since a December 2021 letter to sample wells or provide bottled water there. DNR currently provides the bottled water. The Town of Peshtigo is exploring municipal water for that area.

Sources: Wisconsin DOJ press release, June 4, 2026; WPR; DNR Marinette PFAS page.

French Island (La Crosse County)

PFAS from firefighting foam use at the La Crosse Regional Airport contaminated private wells on French Island in the Town of Campbell. The state has provided bottled water and pursued municipal water connection options. [UNVERIFIED] current 2026 status of the permanent water supply solution and any settlement. Check the DNR PFAS Interactive Data Viewer and DNR’s La Crosse-area PFAS pages before relying on anything here.

What to monitor for all PFAS items.

• DNR PFAS Interactive Data Viewer, for known contamination, municipal test results, and fish advisories
• BRRTS / Bureau for Remediation and Redevelopment Tracking System for open cleanup sites near a parcel
• Whether the legislature releases the NR 140 groundwater standards rulemaking from the REINS Act block
• Federal action: EPA under the current administration has signaled interest in revisiting the 2024 federal MCLs. Wisconsin’s NR 809 standards are state law and would survive a federal rollback

---

3. Nitrate from agriculture

What it is. Nitrate-nitrogen from commercial fertilizer, manure, and septic systems moving into groundwater. The health standard is 10 mg/L (equivalently 10 ppm) as nitrate-nitrogen, tied to methemoglobinemia risk in infants, with a growing literature on colorectal cancer and adverse birth outcomes at lower levels.

Why it matters to a landowner. NitratenitrateFertilizer and manure that has leached into groundwater. Above 10 milligrams per liter it is a health risk, especially for infants, and you cannot fix your neighbor's fields. is the most widespread groundwater contaminant in Wisconsin, and it is invisible, odorless, and not removed by a standard carbon filter. Treatment requires reverse osmosis, ion exchange, or a new deeper well. None of that is cheap and none of it is a one-time cost.

Where it is worst. The Central SandsCentral SandsA sandy farming region in central Wisconsin with heavy irrigation. It is the epicenter of the state's groundwater drawdown fights. (sandy soil, irrigated row crops, fast recharge) and the karstkarstCracked limestone bedrock under thin soil. Contamination at the surface can reach the groundwater in days instead of decades. Common in northeast Wisconsin. counties of northeast Wisconsin.

Status, July 2026. The private well testing picture is the core problem: Wisconsin does not monitor private wells. Testing is entirely at the owner’s discretion. Roughly a third of the state’s population drinks from a private well.

2025 Wis. SB 45, the governor’s budget bill, proposed expanding the well compensation program to cover wells producing at least 10 ppm nitrate-nitrogen or 10 ppb arsenic, with a tiered claim priority by nitratenitrateFertilizer and manure that has leached into groundwater. Above 10 milligrams per liter it is a health risk, especially for infants, and you cannot fix your neighbor's fields. concentration. That provision was not enacted.

What to monitor. Test before you close. Nitrate, coliform bacteria, arsenic, and (near any suspected source) PFAS. Use a state-certified lab; the UW Soil and Forage Lab and county health departments can direct you. Retest seasonally, since nitrate concentrations swing with recharge.

---

4. CAFO expansion and manure spreading over karst

What it is. KarstkarstCracked limestone bedrock under thin soil. Contamination at the surface can reach the groundwater in days instead of decades. Common in northeast Wisconsin. is fractured carbonate bedrock, riddled with sinkholes, crevices, and conduits that carry surface water to groundwater in hours instead of years. Northeast Wisconsin (Kewaunee, Door, Brown, Manitowoc, and parts of Calumet) sits on fractured Silurian dolomite. About 85 percent of wells in that region draw from it.

Why it matters. Manure spread on a field over shallow karst does not filter. It arrives.

Kewaunee County numbers.

A federal study released in 2021 found cow manure to be the number 1 predicted source of acute gastrointestinal illness from private wells in Kewaunee County, ahead of human septic sources.

Status, July 2026. The Silurian bedrock performance standards (Wis. Admin. Code NR 151, adopted 2018) restrict manure application over shallow bedrock and are phasing in over roughly 10 years as CAFOCAFOA large industrial livestock operation. In Wisconsin water disputes it is usually the source of the nitrate and bacteria showing up in neighbors' wells. permits are reissued. Contamination rates have declined measurably since 2015, and E. coli positive wells dropped from 2 to 2.7 percent in 2021 to 0.4 to 1.5 percent in 2022-2023. The standards do not fully address nitrate.

Clean Wisconsin v. DNR, 2021 WI 71 confirmed DNR has explicit authority under Wis. Stat. 283.31 to impose animal unit maximums and off-site groundwater monitoring on CAFOCAFOA large industrial livestock operation. In Wisconsin water disputes it is usually the source of the nitrate and bacteria showing up in neighbors' wells. discharge permits. See Wisconsin water law, section 8.

What to monitor. Depth to bedrock at the parcel (WGNHS county geology and the well log). Distance to the nearest CAFO and its manure storage. Whether the property sits in a Silurian bedrock performance standard area. County land and water conservation department well testing results by township.

Sources: Kewaunee County Groundwater Collaboration Workgroup Final Report; Kewaunee County 2023 Coastal Management Grant final report; Wisconsin Watch, June 2021.

---

5. Central Sands groundwater drawdown

What it is. Cumulative drawdowndrawdownHow far the water level drops while a pump is running. from roughly 3,000 high capacity irrigation wells in a shallow, sandy, surface-water-connected aquiferaquiferUnderground rock or sand with water in the spaces between the grains. It is not an underground lake. Water seeps through it slowly, often only feet per year. across Portage, Waushara, Adams, and Marquette counties.

Status, July 2026. The science is settled and the law is stuck.

The DNR’s Central Sands Lakes Study, completed 2021, found significant, ecosystem-level water level reductions at Long Lake and Plainfield Lake, and reductions at Pleasant Lake near the significance threshold. Long Lake’s impact traces to the collective drawdowndrawdownHow far the water level drops while a pump is running. of about 200 irrigation wells within about 5 miles. Roughly 140 wells within 4 miles drive Plainfield’s. The Little Plover River, a class I trout stream near Stevens Point, has run dry in stretches.

DNR recommended a regional water use district. The legislature has not created one, as of July 2026.

The legal gap: Clean Wisconsin v. DNR, 2021 WI 72 restored DNR’s authority to consider a proposed well’s environmental effects when presented with concrete scientific evidence. Wis. Stat. 281.34(5m), created by 2013 Wis. Act 20, separately bars any person from challenging an approval on the ground that DNR failed to consider cumulative impacts. Both are currently good law. See Wisconsin water law, section 8.

Why it matters to a landowner. If you are buying acreage in the Central SandsCentral SandsA sandy farming region in central Wisconsin with heavy irrigation. It is the epicenter of the state's groundwater drawdown fights., the risk is not that your well is illegal. It is that your neighbor’s 200 neighbors are collectively lowering the water table under you, and Wisconsin has no mechanism to stop them.

What to monitor. New high capacity wellhigh capacity wellIn Wisconsin, a well (or all wells on 1 property combined) capable of pumping 100,000 gallons a day or more. These need DNR approval. An ordinary house well does not. approvals within 5 miles, on the Water Quantity Data Viewer. Long-term water level monitoring wells (DNR and USGS). Any legislation creating a water use district or repealing 281.34(5m).

---

6. Lake Michigan levels and shoreline erosion

What it is. Lake Michigan-Huron swings roughly 6 to 6.5 feet between its record low (2013) and record high (2020). The swing is driven by regional precipitation and evaporation, and nobody can forecast it more than about 6 months out.

The recent cycle.

Why it matters for buying lakefront. Two failure modes, in opposite directions.

Buying at a low-water moment: the beach you are walking on may not exist in 8 years. Bluff recession from a 2012-to-2020-style rise is permanent. Glacially derived coastal bluffs do not rebuild when the water drops. A structure sited to today’s shoreline can be inside the erosion hazard zone at the next peak.

Buying at a high-water moment: you pay for armoring you may not need, and you may buy a property whose seawall is already failing.

A 2021 study in the Journal of Great Lakes Research concluded the 2012 to 2020 habitat loss rate “will become the new normal in the coming century as enhanced variability in water levels facilitates sustained coastal land loss.”

Practical guidance from coastal researchers: periods of average or low water are the time to move infrastructure back from the shore, plant dune grass, and let natural vegetation recolonize. Armoring is the expensive last resort.

What to monitor. Wisconsin Coastal Resilience monthly updates. USACE Detroit District 6-month Great Lakes water level forecast. County bluff recession and erosion hazard mapping (Ozaukee, Milwaukee, Racine, Kenosha, Manitowoc, and Sheboygan counties each maintain some version). Historic aerial photography for the specific parcel, going back to the 1930s if available.

Sources: May 2026 Water Level Update; MSU shoreline outlook, June 2026; Theuerkauf et al., J. Great Lakes Res. (2021).

---

7. Active 2026 Wisconsin legislation

The 2025-2026 regular session ended March 23, 2026. Nothing major on groundwater, wells, or shoreland zoningshoreland zoningCounty rules controlling what you can build within 1,000 feet of a lake or 300 feet of a river. They set your setbacks, your buffer, and how much of the lot you can pave. was enacted.

The practical upshot: the notification bill’s failure means a private well owner in Wisconsin still has no systematic way to learn that contamination has been documented nearby. That is a due diligence burden that falls entirely on the buyer.

What to monitor. The 2027-2028 session convening in January 2027. Reintroduction of the notification act. Any REINS Act carve-out for the PFAS groundwater rule. Wisconsin Conservation Voters bill tracker.

---

8. Cross-cutting: the private well blind spot

Not a single threat so much as the structural feature that makes all the others worse.

If you are buying a property on a private well in Wisconsin, you are the regulator. Budget for a full independent water quality panel before closing, and make the result a contingencycontingencyA condition written into a purchase contract that lets you walk away if something checks out badly. Drafting these well costs an hour of attorney time and is the cheapest protection in the whole process..

---

Related

• Wisconsin water law
• Great Lakes Compact
• Key agencies and data sources
• Module index