[1] United States Environmental Protection Agency (EPA) standards, published in 40 CFR Parts 280 and 281,[2] mandate double-walled piping for many below-ground transport systems in wastewater treatment plants and at sanitary or hazardous-waste landfills or remediation sites.
These and other regulations affect below-grade transport of hazardous materials in fuel storage systems, tank farms,[3] drainage or runoff from process plants, and some food-processing and related applications.
Double-walled containment systems are also used for certain classes of toxic or corrosive chemicals, mostly gases, used in semiconductor fabrication.
Double-walled pipe system may use plastic pressure pipe systems materials of high-density polyethylene (HDPE), polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polypropylene (PP), polyvinylidene fluoride (PVDF), and ethylene chlorotrifluoroethylene copolymer (ECTFE).
Dual-wall stainless steel tubing is most commonly used in semiconductor plants for the containment of highly toxic gases.