ATTACHMENT
Pacific Avenue Sewer Lift Station
100-Year Present Value Analysis Summary
Station
Construction
Replacement
Cost
Continued Operation
Present Value
(100-Year)
Remove from Service
Present Value
(100-Year)
Total
100-Year
Savings
Pacific
Ave
$3,248,000
$20,026,273
$5,099,000
$14.9M
100-Year Present Value Cost Comparison
Cost Description Continued Operation Removal from Service Planning/Design/CM & Inspection $ 3,030,303 $1,000,000 Pump Station Improvements $ 6,696,970 N/A
Force Main Replacement $ 613,000 N/A
Gravity Pipeline & Appurtenances N/A $4,099,000
Operations & Maintenance $ 9,686,000 Negligible
TOTAL $20,026,273 $5,099,000
100-Year Present Value Cost Comparison Assumptions & Calculations Simplified present value 100-Year useful life analysis Sewer Lift Station useful life = 33 years
Gravity and force main pipeline useful life = 100 years $1 million for planning, design, CM & inspection cost per major capital replacement Construction costs base on basis of design report (BODR) cost estimates Pacific Ave Sewer Lift Station constructed in 1953 (approximately 70 years) Major mechanical and electrical retrofit in 1997 (approximately 25 years ago)
Operation and Maintenance (O&M) Costs
Lift station operation is usually automated and does not require continuous on-site operator presence. However, weekly inspections are typically conducted to ensure normal functioning and to identify potential problems. Lift station inspection typically includes observation of pumps, motors and drives for unusual noise, vibration, heating and leakage, check of pump suction and discharge lines for valving arrangements and leakage, check of control panel switches for proper position, monitoring of discharge pump rates and pump speed, and monitoring of the pump suction and discharge pressure. In addition, bar screens are typically maintained to remove coarse materials from the wastewater, collected in containers and disposed of at a sanitary landfill site as needed. Furthermore, odor control chemicals are added ahead of the lift station, and supplied and replenished on a regular basis. The following table outlines the estimated annual O&M costs for the Pacific Ave Sewer Lift Station.
O&M Cost Estimate for Pacific Ave Sewer Lift Station
Cost Description Estimated
Annual Cost
Notes
Labor $ 87,360 Avg. 8 hours per week @ $210 FBR
Materials $ 5,000
Electrical Power $ 4,500
Estimated Annual TOTAL $ 96,860
Estimated 100-Year Cost $9,686,000