Coordinated Water System Plan - Kitsap County Government

Kitsap County May 9, 2005
Coordinated Water System Plan
Regional Supplement 2005 Revision
There are approximately 16 municipal WWTPs in the County but only six currently discharge a
large enough quantity to be considered for a reuse project. The volumes of discharges vary with
the largest effluent flows being from the Bremerton, Central Kitsap, and Port Orchard
wastewater treatment plants.
Wastewater treatment plants are a good source for water reuse. The total average day
wastewater effluent from WWTPs in the County is 10.71 million gallons per day (mgd)
compared to the current 27 mgd average daily potable water use, based on available data. Reuse
could be effective in reducing demand on public water systems but the water savings may be
limited by demand for reclaimed water and high distribution costs.
Wastewater from industrial plants is another potential water source that could be reused either
within the industries operations or externally to meet other water needs. Wastewater effluent
flows were obtained for only a portion of the industries in the County. Based on the available
data, some industrial effluent flows are highly seasonal due to industrial operations. Industrial
wastewater flows are small compared to municipal flows.
J4.2 Stormwater
Stormwater is another potential source of reclaimed water. Stormwater can be utilized for
reclamation purposes. However, there are two main factors that make stormwater reuse less
desirable than wastewater reuse: seasonal variations in flow and the potential for highly
unpredictable water quality. Water rights would also need to be obtained in order to reclaim
stormwater. In general, wastewater reuse is more appropriate than stormwater reuse for the
applications most likely to be implemented within the County. Improved diversion of larger
quantities of storm water to recharge is a potentially attractive process that can be pursued on
both a small and large project basis.
Stormwater flow is incompatible with many water reclamation options because high flows occur
during winter months and low flows occur during summer months. In the summer, when reuse
applications such as irrigation and cooling tower use require the greatest amounts of reclaimed
water, the amount of available stormwater is at its lowest during the year. Rainfall during
summer months is minimal, and any winter stormwater volumes detained are gone by midsummer
due to evaporation and infiltration. Without large storage facilities retaining winter
stormwater for summer use, stormwater reuse does not provide an adequate volume of water for
these applications.
Other water reclamation applications may be able to make use of the timing of stormwater flows.
Direct aquifer recharge is independent of time of year, and can utilize large volumes of reclaimed
water during the winter. This process is referred to as Aquifer Storage and Recovery (ASR).
Stormwater reuse is attractive for this application. However, treatment requirements remain the
same as those for reclaimed wastewater effluent, in order to produce high quality water for reuse.
Therefore, additional infrastructure would be needed to consolidate and treat the stormwater.
These capital improvements would be much greater than those needed to enhance the already
existing treatment facilities associated with wastewater.
Appendix J Section J4 –Potential Sources for Reclaimed Water J4-3