The Positive Impacts of Water Recycling and Reuse in our Environment
February 13, 2015
Water conservation, recycling, and reuse are key to reducing water resource and environment degradation and depletion. This can be achieved by reducing water diversions and reducing the impact of wastewater discharges on environmental water quality.
Water recycling and reuse generally
- increases the available supply of water, and
- meets human water needs with less fresh water.
The intent of water recycling and reusing is to lessen the impact on water environments while meeting substantial and sustainable water needs. Water recycling technologies and project economics and sustainability evaluations still need to be improved. However, focused efforts can reverse water environment decline while meeting water resource needs in a sustainable way. The recycling process improves overall environmental water quality as well as reduces the demand imposed on safe freshwater sources.
Treated wastewater is commonly discharged to rivers and lakes that are subsequently used as drinking water sources. Water supply demands have made treating wastewater flows and returning them to streams of origin a valuable and readily available source of raw water. Unless applied to beneficial reuse, most developed areas implement high treatment and recycling standards As a result, recycled water constitutes a substantial proportion of the base flow in many rivers.
Various sanitation districts use recycled water to recharge a potable groundwater water supply through surface spreading basins. The recycled water is initially disinfected and then upgraded by additional filtration prior to discharging into the groundwater supply. In other areas, treated water is injected under pressure into a heavily-used potable aquifer. The detention period before water is drawn for supply varies according to location. For particular areas this process ultimately prevents salt water intrusion. Other reclamation plants discharge their recycled water into drinking water reservoirs which remain there for a detention period.
Recycle / reuse water quality issues, such as pathogens, organics / inorganics, are the same as for any potable water supply project. Since the recycled water originated from wastewater, treatment technologies must address higher levels of microbiological and chemical contamination to ensure safe drinking water as well as for environmental concerns.
Agriculture / Irrigation
Crop yields have increased in areas where rainfall is low and/or soils are poor, due to treated wastewater that is percolated into aquifers, which provides additional/natural treatment. This method also increases groundwater recharge, creates new aquifers, and increases local stream base flows.
Reclaimed water is encouraged for use for urban and residential landscapes industrial processes, air conditioner chiller water, and fire protection backup, as well as ornamental lakes and car washes. Drought-ravaged areas use recycled water for toilet flushing in new high-rise and housing developments, and sporting venues. Discharge of fresh water is limited in areas near salt water in an effort to reduce damages to environmentally-sensitive salt marsh environments.
Recycled water is used for power station cooling and boiler feed water needs. Microfiltration and reverse osmosis treatment is used to produce potable water grade, which is further-treated to de-mineralize, to provide purified water for power station turbines. Steelworks use recycled water for cooling water and quenching blast furnace or coke oven slag. High tech / semiconductor industries use recycled water high-purity water for their operations.
Water conservation, reuse, and recycling can greatly increase the benefits obtained from limited supplies of freshwater. The water balance in a river basin improves when downstream river flows are altered from reductions in water demands. Water conservation and efficiency in agricultural and urban areas together with reclaimed water flows result in less high discharge pollutants as well as amounts of extracted freshwater, ultimately resulting in improved downstream water quality.
Connor Pincus Group. Consulting Engineers.
Address: 1196 Toorak Road, CAMBERWELL, VIC 3124
Phone: (03) 9835 5000
Fax: (03) 9835 5050
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