An Environmental Impact Study on the Manufacture, Production, and Transport of Septic Systems.

Global concern is growing over natural resource consumption and climate change. Many governments, companies, and industries are taking action to reduce the environmental footprint associated with material and product manufacture and processing. Both natural resource consumption and greenhouse gas emissions are being monitored closely as resource shortages and emissions continue to rise globally.    

Onsite wastewater treatment systems have historically been composed of concrete septic tanks and stone/pipe drainfields. However, the processes and materials used to manufacture conventional systems use a large amount of resources (aggregate, water, fuel, electricity) and emit a large amount of CO₂. Alternatively, other materials have been increasingly substituted for conventional materials, including recycled thermoplastic septic tanks and chambers. These materials have qualitatively been considered more environmentally friendly, but no quantitative comparison has been evaluated in regards to resource consumption and carbon emissions.

 Therefore, the environmental impacts of both conventional septic systems and systems using recycled thermoplastics were evaluated. A conventional septic system was defined as a precast septic tank and gravel/pipe drainfield. Infiltrator Systems Inc. (Infiltrator) products, the IM-1060 and Quick4 Standard chambers, were used to represent recycled thermoplastic systems. Water consumption, electricity consumption, fuel consumption, and carbon emissions were evaluated through raw material production, product manufacturing and transportation for both systems.

 It was determined that even when transporting the recycled thermoplastic systems 1000 miles and conventional systems only 30 miles, the recycled systems reduced electricity consumption by 85% (5296 kWh saved), fuel consumption by 56% (16 gal saved), water consumption by 92% (393 gal saved), and carbon emissions by 81% (1190 kg C saved). When compared to the total number of septic systems installed each year (26.1 million in 2007, USEPA), this could amount to a total savings of 138 billion kWh of electricity, 417.6 million gallons of fuel, 10.3 billion gallons of water, and 31 million tons of carbon if every septic system was composed of recycled thermoplastics rather than conventional materials.