Almost 8 million tons of wastewater is produced in the state of Texas each year. This includes sewage and water from residential, industrial and commercial drains. It isn’t all bad; greener treatment of waste from toilets and sewers produces a sustainable source of compost, called dry sludge.Sludge is a thick mud left over after bacteria have digested sewage and human wastes deposited into septic systems. Untreated sewage contains chemical elements and toxins. Pollutants and pesticides from run-off into open drainage grates contaminate our wastewater. Beneficial bacteria clean and filter the sewage. This leaves a sustainable sludge behind which is left to dry before entering any landfill or used in an application with the land. Texas produces about 650 000 tons of environmentally-friendly, dried sludge per year.The Texas Commission on Environmental Quality regulates treatment of sewage and sludge to make it useful. Elements such as phosphorous and nitrogen are beneficial to soil. Sludge can also be composted with vegetation and landscape trimmings for use on golf courses, large open areas and highways.Austin, Houston and Dallas, produce compost called, Dillo Dirt. The program was initiated in Austin in 1989 and continues today in Houston and Dallas, as well. The municipality collects yard waste and landscape trimmings which are combined with treated with dried sludge. Dillo Dirt is free from human and plant pathogens. They are eliminated during composting when the temperature can be as high as 130 to 170 degrees Fahrenheit. Next, the Dillo Dirt is cured, sifted and packaged.Dillo Dirt can be used on flower or vegetable gardens, as a topsoil dressing or for any other environmentally-friendly outdoor purpose. This fertilizer is rich, made from recyclable elements and will retain water better than regular soil, thus reducing the need for watering.