Wastewater Resource Reclamation

Wastewater Treatment Division (WTD)

M1 Reclaimed water volumes met

About this performance measure: This measure tracks the amount of wastewater that DNRP converts into a resource — reclaimed water.

2007 Results: 292.5 Million Gallons (MG)/year

2007 Target: 260 MG/yr

2008 Target: 300 MG/yr

Influencing factors: Both WTD treatment plants continue to reclaim all water needed for their own operations and any needed by customers. South Plant continued to use reclaimed water for nearly all their compatible internal process needs and irrigation demand. This accounted for about 95% of all reclaimed water used in 2007. The offsite acreage irrigated with reclaimed water in 2007 and 2006 was nearly the same.

Strategy going forward: DNRP's success in converting wastewater into a resource will depend on the cost of providing treatment and conveyance for reclaimed water relative to the cost of using existing sources and/or providing new sources of surface and groundwater. DNRP will be developing a regional water supply plan that will address the role of reclaimed water in meeting the region's diverse water supply needs. There are plans to irrigate Foster's Links (18-hole gold course in Tukwila) with reclaimed water starting in summer 2008. This will increase offsite reclaimed water use from South Plant substantially.

M2 Biosolids reuse targets met

About this performance measure: This measure represents WTD's ability to produce biosolids, a nutrient-rich organic material produced by treating wastewater solids.

2007 Results: 100 percent

2007 Target: 100 percent

2008 Target: 100 percent

Influencing factors: Several projects are under way at the treatment plants to improve biosolids quality and reduce digester problems that will help us maintain a target of 100 percent reuse of biosolids. Although 100 percent of available biosolids were reused, the measure requires ongoing attention to ensure this high rate. Truck Haul capacity/availability and access to application sites will have the greatest impact on this measure.

Strategy going forward: WTD's strategy for continuing to meet the target of 100 percent biosolids reuse has several components that include:

• Ensuring availability of reuse sites for 150 percent of biosolids production.
• Continuing an aggressive industrial pretreatment program to maintain current low metals levels.
• Maintaining an active research and demonstration program that responds to public concerns and identifies potential new uses for biosolids.
• Investigating Class A technologies and determining which ones would be most appropriate and cost-effective for the West Point and South Plant facilities.

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