Sustainable Building Technical Manual - Etn-presco.net

SHALLOW TRENCH SECTION VIEWSource: City of Austin, Environmental and Conservation Services Department, Sustainable Building Sourcebook. (Austin: City of Austin, 1993).Water Reclamation❑ Use reclaimed water for purposes such as toilet-flushing if dual distribution linesare in place.Reclaimed or reused water is wastewater effluent from a centralized water treatmentplant that is reused in a variety of ways: for fire protection, in outdoor water features,for street cleaning, for wetlands recharge, or for industrial purposes such as coolingwater, boiler-feeder water, or process water.❑ Check local regulations on use of reclaimed water.No federal regulations regarding water-reuse practices currently exist, although theEPA has published a manual on the subject (see “Resources”). Many states have adoptedwater-use regulations, but these vary considerably. According to a survey conductedin 1992, 18 states had adopted regulations for reclaimed water reuse, 18 states hadguidelines or design standards, and 14 states had no regulations or guidelines. Most ofthe standards in place pertain to urban or agricultural irrigation. Regulations in somestates (Arizona, California, Florida, and Texas) strongly encourage water reclamation asa conservation strategy. Regulatory guidelines for water reclamation usually pertain toreclaimed water-quality and treatment requirements, water-monitoring requirements,reliability of treatment facilities, storage requirements, irrigation application rates,groundwater monitoring, and property-line setback distances for applications. Theobjective of these regulations is usually to maximize resource benefits while protectingenvironmental and public health. 12❑ Apply reclaimed effluent to land.This technique works best with wastewater treatment of at least 10 million gallons perday. Effluent can be distributed on golf courses, farmland, orchards, or other land. Thisalternative to discharging treated wastewater into streams and waterways has severalbenefits, including biological treatment of wastewater, recharging of groundwater, useof the water as a resource, and protection of surface-water quality. In some areas, anhydraulic irrigation-control and -release system is used, diverting effluent to a holdinglagoon during wet seasons when irrigation is not needed. Permitted discharges arereleased from the lagoon to a waterway as necessary. The system can be fully automatedand provide for flexible use.❑ Establish site-specific monitoring procedures.When using reclaimed water for irrigation or land application, monitor to controloverwatering and detect buildup of nitrogen, phosphorus, potassium, calcium, iron,and sodium.Figure 6