Reuse: Environmental and Recreational
Content Table
Restoring streams and wetlands
In recent years many wastewater treatment plants have been upgraded to meet increasingly stringent environmental requirements for discharge to receiving waters. The effect of moving from treated effluent quality discharges to recycled water quality discharges is assisting in the preservation and enhancement of the aquatic environment in many locations.
Examples of stream restoration include:
· San Luis Obispo, California: Recycled water from the treatment plant is used for industrial and landcape irrigation needs, but is also used to meet regulatory minimum discharge requirements to maintain environment flows for endangered fish species in San Luis Obispo Creek downstream of the city. The recycled water discharges provide improved in-stream environmental conditions in summer.
· Japan: There has been extensive use of recycled water to restore degraded urban streams. In Tokyo, 43,300 m3/d of recycled water has been used to restore flows in the Nobidome and Tamagawajousi channels (Ohgaki & Sato, 1991). In Nagoya, 7400m3/d of recycled water has been used to restore flows in the Arako River (Ogawa, 2001).
· Sydney, Australia: A scheme will be constructed to supply up to 50,000m3/d of recycled water to provide environmental flows in the Hawkesbury river downstream of the main water storage. The scheme will make additional freshwater available to supply Sydney.
Creating of new wetlands
Recycled water can also be used to create new wetlands to provide additional habitant for waterbirds and other species.
In 1986, the City of Arcata in California created the Arcata Marsh and Wildlife Sanctuary by construction of wetland which provides additional natural treatment for recycled water from its treatment plant before discharge into Humboldt Bay which is an oyster farming area. The wetland area includes walking trails and a wildlife education centre.
Creating new ornamental and recreational waters
The City of San Antonio in Texas has created the San Antonio River Walk where natural stream flow is augmented with groundwater and recycled water.
The Metropolitan Government of Tokyo has made extensive use of recycled water to restore degraded urban streams and provide public recreation areas.
Recycled water from the City of Santee near San Diego, California, has been used to create the 77ha Santee Lakes Recreation Preserve including 33ha of open water. The lakes were created as an alternative to constructing an expensive discharge pipeline to the ocean. The Preserve, which was opened to the public in 1961, now receives more than 550,000 visitors annually and is fully self-supported through user fees. The treatment plant was upgraded in 1995 and the recycled water now meets California regulations for full body contact recreation. Recreational activities permitted at Santee Lakes include fishing boating and camping.
Other Uses
In the Australian ski-fields, recycled water is being used for artificial snowmaking. When natural snowfalls are low, recycled water is sprayed into the air at night to produce extra snow cover on the ski slopes. Filtered and disinfected recycled water is used.
Related Articles
References
Asano, T. et al (2007) Water reuse: issues, technologies and applications, McGraw-Hill New York, ISBN-13: 978-0-07-145927-3, Part 4: Water Reuse Applications,
- Chapter 21: Environmental and Recreational Uses
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