When you’re building in Teton Valley — whether in Victor, Driggs, Cedron, or Tetonia — or across the state line in Alta, WY, you can’t treat your septic system like an afterthought. Harsh winters, hot summers, and variable soils mean the wrong septic tank choice can lead to expensive repairs down the road.

At ParkFab, we’ve installed hundreds of systems, and owner Shawn brings a rare insider’s perspective: he used to work in concrete coatings for sewer rehabilitation — literally repairing the exact problems that plague poorly chosen or poorly maintained tanks. His experience means you get a system designed to last decades in local conditions.

What Is a Polyethylene Septic Tank?

A polyethylene septic tank is made from high-density, non-porous plastic that can withstand underground pressure, extreme temperature swings, and shifting soils without cracking or corroding. Unlike concrete tanks, which can suffer from frost damage, chemical corrosion, and leaks over time, poly tanks are lightweight, seamless, and virtually maintenance-free.

Concrete vs. Polyethylene: The Real-World Differences

Feature Concrete Septic Tank Polyethylene Septic Tank
Weight Extremely heavy; requires large equipment to move Lightweight; easier to transport and install
Durability in Freeze-Thaw Can crack or spall in extreme temperature swings Flexible and resistant to cracking in -40°F to 90°F climates
Corrosion Resistance Vulnerable to H₂S gas corrosion — hydrogen sulfide in septic systems turns into sulfuric acid that slowly eats away at concrete from the inside Non-porous, corrosion-proof
Installation Time Slower; more equipment and labor Faster installation with less disturbance
Leak Risk Joints and cracks can develop over time Seamless molded design reduces leak risk
Soil Suitability Performs well in stable, dry soils Works in wet, high-groundwater, or shifting soils
Cost Sometimes lower upfront Slightly higher upfront, but often cheaper long-term

Why H₂S Corrosion Matters

Hydrogen sulfide (H₂S) gas is a natural byproduct of septic systems. When it reacts with moisture inside concrete tanks, it forms sulfuric acid, which breaks down the concrete over time — often without you noticing until there’s a major leak or structural failure.

Shawn’s background in sewer rehab coatings means he’s seen this damage up close — and fixed it. That’s why, when code allows, he recommends poly tanks: they’re impervious to H₂S and won’t deteriorate from the inside out.

Why Poly Tanks Shine in Teton Valley

Teton Valley isn’t easy on infrastructure:

  • Extreme temperature swings (-40°F winters to 90°F summers)

  • Variable soils — from clay-heavy to sandy to high groundwater

  • Seasonal frost heave that shifts underground systems

Polyethylene tanks handle these conditions without cracking, leaking, or moving out of place. And because they’re lightweight, installation is faster and less disruptive to your site.

A Note for Alta, WY

In Wyoming, code only allows concrete tanks. That doesn’t mean you’re stuck with a short lifespan — it just means you need the right installation approach.

Shawn applies his knowledge from concrete coating and rehab work to:

  • Choose concrete tanks that perform best in local soils

  • Ensure proper placement and bedding to limit freeze-thaw stress

  • Use installation techniques that help slow H₂S corrosion

The ParkFab Installation Difference

We don’t just set a tank in the ground and walk away. ParkFab septic installs include:

  • Site & soil assessment to determine optimal placement and depth

  • Precise excavation that minimizes disturbance

  • Insulation & frost protection where needed

  • Coordination with other trades so your project stays on schedule

Whether you’re building your dream home or upgrading an older system, we’ll recommend the right tank for your property — and install it so you don’t have to think about it again for decades.

📞 Call Shawn at ParkFab: 208-360-2411
📧 Email: shawn@parkfab.com