Community Water Supply Efficiency Improvements Potential Savings for the 6 th Power Plan September 30 th, 2008 Regional Technical Forum

Water Supply Overview Processes – Collection – Treatment – Distribution Energy Consumption: – Pumping 80% – Treatment 20% – New regulations for treatment may change the mix slightly » Ozonation » Membrane Filtration » UV Disinfection Source Type – Surface Water » More treatment energy » Less pumping energy – Ground Water » Less treatment energy » More pumping energy

Community Fresh Water in the PNW USGS: 80% of PNW Population served by Community Water Systems 56% is Surface Water * 43% is Ground Water * EPA: 4,570 community water systems in the 4 PNW states. 240 plants serve 80% of population served by CWS’s * By volume

An In-Depth Look at the Largest Supplier: Seattle Public Utilities Serves a retail population of nearly 650,000 (6% of PNW population) Also wholesales water to water utilities serving a population of over 700,000 (6%) The next four slides are from Seattle Public Utilities…

Energy Savings Measures VFD’s and low head loss valves Distribution system pressure optimization (strategic use of booster pumps) Fix leaks in distribution system Optimize filtration (pre-treat before filtering) Pump efficiency optimization Premium efficiency motors Low pressure UV lamps versus med. pressure High efficiency single stage blowers Compressed air efficiency measures Use of low friction linings or coatings in piping Lighting

5 th Plan Total Energy Use: – 117 aMW Technical Potential: – 29 aMW Economic Potential: – 25 aMW – 1.3 cents/kWh Assumptions: 20% savings Costs same as wastewater O&M/NEB’s same as wastewater

6 th Plan (proposed): Energy Consumption Data Assuming: Groundwater = 1800 kWh/MG Surface Water = 1400 kWh/MG PNW Energy Use (2008) Groundwater: 72 aMW Surface Water: 73 aMW Total = 145 aMW

6 th Plan Assumptions (proposed) Achievements Since 5 th Plan – ETO 20 Projects Savings = 0.8 aMW (at $6.7million) Savings cost $0.92/kWh Energy use tracks with population increase Energy savings = 15% – Very limited data: BacGen (2003) 7% to 23% Technical Potential: 27aMW Cost: $0.92/kWh? Measure Life: 10 years?

Data Needs Plant Energy Use Measure Savings – Energy Savings – Non-Energy Benefits Measure Cost O&M Costs