HDPE Geomembrane Liners: Ultimate Containment Barrier for Power Plant Fly Ash & FGD Gypsum Storage

The Critical Challenge: Contaminated Power Plant Byproducts

Thermal power generation produces high-risk waste streams:

• Fly Ash: Contains heavy metals (As, Se, Hg, Pb) and radioactive elements

• FGD Gypsum: Sulfur compounds and chlorides with pH extremes (2-12)

• Bottom Ash: Abrasive slag particles that degrade conventional liners

Uncontained leachate triggers:
⚠️ Groundwater contamination exceeding EPA Maximum Contaminant Levels (MCLs)
⚠️ $50k+/day EPA fines under CCR Rule (40 CFR Part 257)
⚠️ Decade-long remediation liabilities averaging $12M/site

Our Solution: Power Plant-Optimized HDPE Geomembranes

 Engineering Advantages for Ash/Gypsum Containment

1. Heavy Metal Leachate Barrier

• Blocks 99.99% contaminant migration (As, Se, Hg at 500 ppb levels)

• Chemical resistance matrix:

  Contaminant	Permeation Rate	Test Standard
  Sulfate	<0.001 g/m²/day	ASTM E96
  Selenium	<0.0003 mg/cm²	EPA Method 1315
  Boron	<0.002 μg/cm²	ASTM D5322

2. Alkaline/Acidic pH Stability

• Maintains integrity in pH 1.5 FGD purge water to pH 12 fly ash leachate

• 200% superior stress crack resistance vs. standard liners (ASTM D5397: >1,500 hrs)

3. Ash Abrasion Defense System

4. Lifetime Cost Reduction

• 60-year design life vs. 20-30 years for compacted clay

• $3.50/sf installed vs. $9+/sf for concrete tanks

• 30% thinner drainage layers with geocomposite protection

5. EPA CCR Rule Compliance

• Meets Subpart D requirements for double-liner systems

• Certified to GRI-GM19 for ash containment

• Third-party CQA documentation package

Technical Specifications: CCR-Optimized Performance

Defense-in-Depth Containment Design

Multi-Barrier Protection System:

1. Geotextile Cushion (600g/m²)

   • Puncture protection from sharp ash particles

2. Primary HDPE Liner (2.5mm)

   • Main chemical barrier (EPDM-free formulation)

3. Leak Detection Layer

   • Geonet with 15m grid monitoring wells

4. Secondary HDPE Liner (1.5mm)

   • EPA-mandated backup containment

CCR-Specific Installation Protocols:

• Robotic Welding for zero-defect seams in critical zones

• Bentonite Swell Strips at pipe penetrations

• Post-Installation Spark Testing at 25kV

Proven Power Plant Performance

"After containing 8M tons of pH 11.2 fly ash since 2012, our HDPE liner system shows <0.01% volumetric change with zero detected leaks."
– Plant Manager, 650MW Coal Facility, Ohio

EPA Compliance Documentation Included:

• CCR Rule Subpart D checklist

• Third-party CQA certification

• Leachate collection design calculations

• 10-year integrity monitoring plan

Financial Protection Package

• 10-year material warranty with contamination coverage

• EPRI-validated service life projection

• Insurance-backed performance bond