Capturing the water you already have: Using alternate onsite sources

Abstract

Onsite sources of water such as air‐conditioner condensate, rainwater, and foundation drain water are often untapped resources that can help save significant volumes of potable water and wastewater. The use of these sources can reduce peak demand on a utility and the subsequent need for future water treatment expansion to meet growing demands. Capital costs are transferred from the utility to the user. Public and private interest in alternate on‐site sources is growing, and there is much opportunity for those who make use of it. However, further development of building codes and regulatory guidance will be necessary to protect public health and promote good design.

Evolving Urban Water and Residuals Management Paradigms: Water Reclamation and Reuse, Decentralization, and Resource Recovery

“…While behavioral changes are encouraged and welcomed, the emphasis here is on the use of technologies that result in reduced water use. A wide variety of approaches are available and are increasingly being applied, as evidenced by the recent May 2008 issue of the Journal of the American Water Works Association Hoffman, 2008;Maddaus et al, 2008;Mayer et al, 2008;Pape, 2008;Smith, 2008). Anecdotal evidence also suggests reduced domestic water use and the corresponding increase in wastewater strength (because per-capita domestic waste loads are independent of water use, reduced water use leaves less wastewater flow to dilute the waste mass).…”

Army Installations Water Sustainability Assessment: An Evaluation of Vulnerability to Water Supply

“…Local regulations often limit the types of water re-use allowed and should be checked before any serious investigation into alternate sources. Other regulations on the usage of alternate sources include EPA regulations on drinking water and backflow prevention and IAPMO's codes regarding non-potable water reuse systems (Hoffman, 2008  Install a graywater system to capture and possibly treat washwater for reuse.  Reuse treated wastewater effluent for irrigation or other appropriate uses.…”

“…The general definition for graywater is used washwater -the byproduct of most indoor water uses including showers, clothes washers, and most sinks, but excluding toilets, and sometimes kitchen sinks and dishwashers (which produce wastewater containing food particles). Graywater needs some amount of treatment before reuse except when being used for subsurface irrigation; even then, however, it needs to be used relatively quickly (if not treated) otherwise it will become septic (Hoffman, 2008).…”

“…‡ Cooling tower blowdown is another potential source of reusable water. Though not necessarily considered gray water, blowdown can sometimes be reclaimed for use without the full menu of treatments provided by a wastewater treatment plant (Hoffman, 2008).…”

“…This results in important differences with regard to the amount and types of pollutants and debris stormwater is likely to pick up. Stormwater tends to gather more debris and is exposed to different and more pollutants than is rainwater (such as oil from roadways, pesticides, trash, etc) (Hoffman, 2008). Due to these potential pollutants, stormwater is more likely to need treatment before use than is rainwater.…”