Decentralized Treatment in the CRD
The CRD has made a bold and innovative move to depart from a traditional centralized approach to wastewater treatment to a more distributed wastewater treatment strategy.
Advantages
The advantages of this distributed treatment approach are three fold. First, it reduces the size of the downstream plants, as the upstream plants reduce the flows reaching the downstream plant. Second, by strategically locating the upstream plants, this approach creates local opportunities for water reuse and heat recovery from the wastewater. Third, by reducing the existing wastewater flows in the lower portions of the sewerage system, capacity is freed up to handle a greater portion of the wet weather wastewater flow – greatly reducing the frequency and volumes of the current sanitary sewer overflows (SSO). A wet weather flow treatment only plant is proposed at Clover Point to handle the surplus flows during wet weather periods prior to discharge to the ocean.
Innovations in Decentralized Treatment
The real innovation of this strategy is the flexibility that it will provide the CRD in the future decades. The CRD will no longer need to build larger and larger pipes in the ground to transport the wastewater long distances to a central treatment plant site. There will also not be the need to continually expand the central plant to handle higher wastewater flows due to growth – the decentralized water reclamation plants will handle growth in the outlying communities. These plants will utilize advanced treatment technologies to take advantage of phasing opportunities and "just in time" construction to accommodate needs.
This strategy will also allow the CRD to continue to incorporate new directions in overall community development. New or redevelopment projects, such as the Dockside Green development, fit well with the strategy adopted by the CRD Board in that they blend the advantages of local water reuse with reduced demands on the water infrastructure, while using the capacity of the community sewerage systems for the management of surplus wastewater flows and residuals management.