Last year, the Associated Press published an investigation that every mobile home park investor should have read. The headline: nearly 70% of mobile home parks operating their own water systems had violated safe drinking water regulations in the prior five years.

Read that again. Seven out of ten.

That’s not an outlier. That’s the baseline. And if you’re buying mobile home parks without making utility infrastructure a top-three due diligence priority, you’re playing with fire.

At Keel Team, we’ve made city water and city sewer a hard requirement in every deal we underwrite. This is why.

What the Data Actually Shows

The AP’s investigation, published in July 2025, found widespread violations across the country: parks that hadn’t conducted required contamination tests in years, others exceeding federal limits for arsenic and other hazardous substances, and infrastructure that in many cases dated back 40–50 years with no documented maintenance history.

The EPA database doesn’t even capture all of it. Many states incorrectly categorize mobile home parks in their regulatory systems, meaning some parks are flying completely under the radar — until something goes catastrophically wrong.

And when it goes wrong, it’s expensive.

The EPA Is Not Playing Around

Earlier this year, the EPA filed a civil complaint against a mobile home park in California for persistent arsenic violations and wastewater system failures. The resulting consent decree mandated full system upgrades and a $50,000 civil penalty.

That’s the resolved outcome. The pre-consent-decree cost? Emergency orders, legal fees, remediation contractors, resident notification requirements, and potential relocation assistance.

And that’s before the ongoing fine exposure: up to $10,000 per day for active contamination violations.

On a 100-lot park, a full water and sewer system replacement runs roughly $200,000–$320,000. On a 200-lot park, that number climbs to $400,000–$640,000. This isn’t contingency-level money — it’s deal-breaking money if it wasn’t in your underwriting.

The Hidden Danger: Sellers Often Don’t Know Either

Here’s what makes this particularly dangerous: this isn’t usually a case of a bad actor seller hiding something. Many mom-and-pop operators who built these parks in the 1970s and 1980s have never done a formal infrastructure assessment. They’ve been managing problems with patch fixes — treating a contaminated well instead of replacing it, using temporary easements instead of connecting to municipal water.

When you close, you inherit all of it. The liability doesn’t stay with the seller.

We’ve heard from operators who closed on parks, received EPA notices of violation within 12 months, and discovered the previous owner hadn’t filed required water quality tests in three or more years. The park had been out of compliance before the ink was dry on the purchase agreement.

The City Water/Sewer Standard: Non-Negotiable

This is the clearest lesson the data supports: mobile home parks connected to municipal water and city sewer systems have dramatically lower EPA compliance exposure.

Municipal systems are regulated, tested, maintained, and backed by infrastructure that isn’t your problem to fund. When you’re on city water and city sewer, the utility liability stops at the street. Everything underground is the city’s responsibility.

Private well and septic systems are the opposite. They’re yours. Every test, every failure, every replacement.

At Keel Team, our acquisition criteria requires city water AND city sewer. No exceptions. It’s not a preference — it’s a hard filter. And the AP investigation is exactly why.

The Due Diligence Checklist: What to Do Before You Close

If you’re actively looking at mobile home parks, here’s the minimum infrastructure due diligence you should be doing on every deal:

1. Confirm utility type immediately — before your LOI.
Ask the seller directly: Are you on city water? City sewer? Do not wait for the due diligence period to find this out. If the answer is no on either, that needs to factor into your price and your decision to proceed.

2. Pull the EPA ECHO database record.
The EPA’s Enforcement and Compliance History Online (ECHO) database is public and searchable. Look up the park’s water system ID. You’re looking for: any notices of violation in the past five years, compliance status, testing frequency, and enforcement actions.

3. Request the last three years of water quality test results.
If the park has its own well system, the owner should have documentation of required testing. No documentation is a red flag — it may mean tests weren’t done, or weren’t filed. Either way, you’re potentially inheriting a violation.

4. Get a professional infrastructure assessment.
Not just a Phase I environmental assessment (though you should get that too). A specific evaluation of the utility systems: water line age and material, sewer line condition, pump station condition, and estimated remaining useful life. A licensed engineer should give you a written opinion.

5. Check with the state health department.
State records often show violations that don’t appear in the federal EPA database. A quick records request can surface issues that have been quietly accumulating.

6. Price the risk into your offer.
If you’re buying a park with private utilities, the infrastructure risk isn’t an automatic reason to walk — it’s a reason to price it appropriately. Get contractor estimates for replacement. Subtract them from your offer. Require an infrastructure escrow at closing if the seller won’t discount.

For a full breakdown of our acquisition due diligence framework — including how we evaluate infrastructure, location, and operational risk — the Keel Team Mobile Home Park Due Diligence Playbook is a practical starting point.

The Bigger Picture

The mobile home park sector has attracted enormous institutional capital over the past decade on the promise of resilient returns and limited supply growth. That thesis is still sound. But it only works if you’re buying quality assets with clean fundamentals.

Water and sewer infrastructure is unsexy. It’s underground. You can’t see it in a proforma. But it’s one of the most consequential variables in any mobile home park acquisition — and it’s where unsophisticated buyers consistently underestimate their exposure.

The 70% violation rate the AP found isn’t a number about bad actors. It’s a number about deferred maintenance, aging systems, and an industry that grew faster than professional oversight could keep up with.

Knowing this is part of your edge. Underwriting it correctly is how you protect your capital — and your residents.