prioritizing booster pump station improvements tom peters, p.e. may 2, 2008
TRANSCRIPT
Prioritizing Booster Prioritizing Booster Pump Station Pump Station ImprovementsImprovements
Prioritizing Booster Prioritizing Booster Pump Station Pump Station ImprovementsImprovements
Tom Peters, P.E.May 2, 2008
City of Bellevue City of Bellevue WBPS Evaluation OverviewWBPS Evaluation Overview
▼ Owns and operates 23 major water booster pump stations
▼ Pumped water service for over 60% of customers
▼ First overall technical evaluation of all pumping facilities and equipment
City of BellevueCity of BellevueWBPS Evaluation Project GoalsWBPS Evaluation Project Goals
▼ Efficient distribution of maintenance dollars Identify facilities whose failure significantly
impacts system reliability Rank WBPS in order of needed
improvement Develop costs to upgrade and Improve
WBPS reliability Asset management “building block”
City of BellevueCity of BellevueWBPS Evaluation HistoryWBPS Evaluation History
▼ Grown from merger and assumption of old water districts
▼ Some facilities developer constructed ▼ Historically wholesale water purchase
from City of Seattle ▼ Member of Cascade Water Alliance
City of Bellevue WBPS Evaluation City of Bellevue WBPS Evaluation Project ChallengesProject Challenges
▼ Multiple pump types▼ Varying levels of
building quality▼ Below grade vaults ▼ Inefficient location of
emergency power ▼ Absence of re-
chlorination facilities
City of Bellevue WBPS Evaluation City of Bellevue WBPS Evaluation Project ChallengesProject Challenges
Pump Station Information and Data
▼ Thorough review of as-builts, maintenance records, water production and previous studies
▼ Analysis of peak and average day consumption, by pump station and operating zone.
▼ Rigorous assessment of each pump station condition, with video taped operator interview
▼ Development of 10 system schematics summarizing basic system information
Ranking Pump StationsRanking Pump Stations
Ranking Ranking WBPS NeedsWBPS Needs
PairedPairedComparisonComparisonNormal OperationNormal Operation
Paired Paired ComparisonComparison
Emergency OperationEmergency Operation
Ranking Evaluation Criteria
Pump Station Score Card
Normal Operating Ranking
49.154.4 56.9 58.6 58.6
63.1 64.7 65.2 65.4 67.4 69.1 71.5 73.8 74.8 75.980.6 82.9 83.3 84.3 84.1
88.595.5
0.0
10.020.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
Sc
ore
(0
to
10
0)
Ranking Pump StationsRanking Pump Stations
Ranking Ranking WBPS NeedsWBPS Needs
PairedPairedComparisonComparisonNormal OperationNormal Operation
Paired Paired ComparisonComparison
Emergency OperationEmergency Operation
City of Bellevue WBPS Evaluation City of Bellevue WBPS Evaluation Risk Based AssessmentRisk Based Assessment
▼ Risk =
Hazard Probability X Vulnerability X Consequence▼ Hazards impacting multiple facilities pose the
greatest risk Regional power outage Earthquake Flooding
▼ Redundancy, properly placed, provides effective mitigation
Sample Risk RankingSample Risk Ranking
0
100
0 50 100 150
Consequence of Failure Score
Lik
eli
ho
od
of
Fai
lure
Per
cen
t
LowestRisk
PumpStations
HighestRisk
PumpStations
Emergency Operating Scenario
31.139.1 42.2
46.7 49.8 52.0 55.6 56.0 56.4 60.0 60.0 63.1 64.0 64.4 64.4 64.4 65.3
74.2 77.881.8
91.196.9
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
Sc
ore
(0
to
10
0)
Combined Rankings
SUMMARYSUMMARY
▼WBPS assessed: 23▼WBPS requiring improvements: 21 ▼Total cost all improvements: 21.4 M▼Average cost of replacement (5): 2.9 M ▼Average cost of improvements (16): 0.43 M