Apr 30, 2013 11:47 PM by Zach Thaxton
The Pinon Rest Area along southbound I-25 north of Pueblo will reopen this summer featuring a new waste system comprised mainly of bark from Ponderosa pine trees. It's an innovative waterless sewage system that turns waste into evaporated water and nitrates for fertilizer.
The rest area was closed last fall when its traditional septic system became overwhelmed by waste from the 2,000 to 3,000 people who utilized its restrooms each day. "During the holidays and our peak periods, we can get up to 8,000 to 10,000 people per day," said Chuck Decker with the Colorado Department of Transportation. "The soils that were in the septic system didn't quite work like we thought they would and didn't absorb the water like it was supposed to."
CDOT decided to go with an innovative mineralizing, evaporative type of sewer system with an expected lifespan of 200 years or more. A basement was added to the rest area and it was filled 18 inches deep with Ponderosa pine bark. "Basically, underneath (the rest area) is a live forest floor," Decker said. It's all wood bark." Micro-organisms in the bark naturally and rapidly decompose the waste. Solid waste is quickly dissolved and the micro-organisms are easily able to keep up with whatever volume of waste is deposited. Liquid waste, which comprises the vast majority of the waste, slowly filters through the bark. "The water gets aerated out of the urine and basically you'll just have a minute nitrate salt crystal left over," Decker said. Even the toilet paper is easily decomposed by the micro-organisms in the bark. "It will last forever," Decker said. "It will never have to be maintained or added to again." Evaporated water from the liquid will be exhausted out via constantly-circulating air throughout the system and will be virtually odorless when it reaches the ground surface, Decker says.
Water-free toilets and urinals and limited water in sinks and from a gentle sprinkler system to keep the Ponderosa bark damp will save an estimated 1.4 million gallons of water per year, Decker says. The estimated cost for the project is $500,000, paid for through CDOT's general operating budget. Reopening is tentatively slated on or around June 1.