More than 60% of the 44,000 manufactured home communities in the United States were built in the 1970s and 1980s. That’s not a footnote — it’s a ticking clock.

When those parks were developed, underground water lines, sewer systems, and service connections were installed that were expected to last 30–50 years. We’re now 40–55 years past that installation date. And while the mobile home park investing industry has exploded in popularity — MHI Congress attendance jumped 59% between 2019 and 2025, and lender interest has increased more than sixfold in just 14 years — the underlying infrastructure of thousands of these communities is quietly reaching end of life.

If you’re buying mobile home parks right now, infrastructure is the single most dangerous thing you’re probably underestimating.

I’ve bought and operated over 50 mobile home parks. I’ve seen what happens when investors get blindsided by a $300,000 water system overhaul they didn’t see coming. This post is designed so that doesn’t happen to you.

Why Infrastructure Is the #1 Hidden Problem in Mobile Home Park Investing Right Now

Unlike a roof or HVAC system, underground infrastructure is invisible until it fails. And when it fails in a manufactured home community, it doesn’t just inconvenience you — it triggers EPA notices, tenant complaints, potential lawsuits, and in the worst cases, boil-water advisories that make local news.

Here’s what’s changed in the past few years:

1. EPA Enforcement Has Gotten Real

The EPA’s Lead and Copper Rule Improvements, which went into effect in 2024, require all community water systems to complete a lead service line inventory by 2027. Mobile home parks that operate their own private water systems are explicitly included. If your park has a private well or water distribution system installed before 1986 — when lead pipe was banned — you may be sitting on a compliance time bomb.

2. State Regulators Are Following EPA’s Lead

Post-COVID, state environmental agencies across the Southeast and Midwest have increased enforcement on private water systems. Tenant water quality complaints are getting follow-up that they didn’t get five years ago.

3. The Parks With Infrastructure Problems Are Now Hitting the Secondary Market

As institutional capital has flooded into mobile home park investing, large operators are cherry-picking the best assets — city water, city sewer, low-maintenance infrastructure. That’s leaving a growing pool of “problem parks” to trickle down to smaller and mid-size operators. If you’re buying parks in the $500K–$5M range, you are now far more likely to encounter infrastructure problems than you were five years ago.

The Three Infrastructure Categories That Should Drive Your Due Diligence

Category 1: Utility Source

Before you get excited about any park, answer this question: Does this community have city water AND city sewer?

If yes — proceed to normal due diligence. You’ve eliminated the biggest risk category. If no — you need to understand exactly what you’re dealing with before you write a number on paper. Private water systems, septic systems, lagoons, and package wastewater treatment plants all carry different risk profiles and cost ranges.

Category 2: Infrastructure Age

When was the park built? If pre-1980, assume the underground systems have never been replaced. A park built in 1972 that’s never had its water lines touched is running on borrowed time. Galvanized steel pipes corrode. PVC from that era gets brittle. Lead service lines were standard practice until 1986.

Always ask for: water system records (EPA system ID if applicable), any prior environmental assessments, maintenance and repair logs, and the age and material of main lines.

Category 3: Regulatory Status

Is the private water system already flagged? Search the EPA’s Safe Drinking Water Information System (SDWIS) database. If the park’s water system has a history of violations, you’ll see them there. A pattern of violations — or an open enforcement action — is a major red flag.

What Infrastructure Problems Actually Cost

Here’s the honest range based on what we’ve seen in real deals:

• Full private water system replacement (50–100 lots): $100,000–$350,000
• Lead service line replacement: $5,000–$15,000 per connection
• Lagoon remediation / closure: $50,000–$200,000+
• Package wastewater treatment plant installation: $150,000–$500,000
• Municipal sewer connection (varies by distance): $50,000–$1,000,000+
• EPA enforcement compliance order: Legal fees alone can run $50K–$100K

None of these are fatal if you price them correctly into the acquisition. All of them are fatal if you find out after you close.

How to Handle Infrastructure Risk in Your Offer

1. Get a professional assessment — hire a licensed engineer to assess the water and sewer systems before or during due diligence. Budget $3,000–$8,000 for a proper evaluation.
2. Price in the remediation cost — whatever the engineer estimates, use that number to negotiate a price reduction dollar-for-dollar.
3. Use an escrow holdback — if the seller won’t reduce price, negotiate to hold a portion of the purchase price in escrow pending infrastructure repair.
4. Walk away from lagoon parks — unless you can get a dramatically reduced price AND the math works including full lagoon closure costs.

For a complete infrastructure due diligence checklist — including the exact questions to ask sellers and what to look for in engineering reports — we’ve documented everything in the Keel Team MHP Due Diligence Playbook, built from 50+ real acquisitions.

The Bottom Line

The mobile home park industry is one of the best investment categories in real estate right now — 20.6 million Americans live in manufactured or mobile homes, affordability pressure has never been higher, and institutional interest has validated the asset class. But the same aging stock that creates opportunity also creates real, expensive risk.

Infrastructure due diligence isn’t optional. It’s the single most important thing you can do before making an offer on a park. The parks with real problems aren’t going to tell you upfront. You have to ask the right questions.

Andrew Keel is the founder of Keel Team Real Estate Investments, a mobile home park investment company with 50+ manufactured home communities across the United States.