Testing Finished Water Meters A Low Tech Approach

Transcription

1 Testing Finished Water Meters A Low Tech Approach John Gilroy, PE City of Olathe, Kansas jpgilroy@olatheks.org 12/5/2017

2 Water Audit Results Unrealistic Performance Indicators ILI = 0.2

3 Olathe, KS Area of 61 square miles 4th largest City in Kansas Population of 130,045 Full Service City 34,860 Water Customers 3

4 OLATHE WATER PLANT SITE Olathe Water Plant 4

5 M LM LM Dual Media Filters Below-grade Clearwell SH Basin 1 M Basin 2 Flowblending Structure PP CO SH FLU AM M POL SH LM SA CA POL LM PP Membranes CA Basin 3 M SH M SH Basin 4 SH FLU Above-grade Clearwell CA SH WATER TREATMENT PLANT 2 CHEMICAL SCHEMATIC - COAGULANT - SODIUM HYPO CO FLU - CARBON DIOXIDE - FLUORIDE POL - POLYMER PP - POLYPHOSPHATE LM - LIME AM - AMMONIA AM To Distribution System

6 History of Olathe Water Plant 1964 Plant Constructed 4 MGD Plant Additions Lime Feed System Additions and Rehab 1998 Plant Expansion 17 MGD 2006 Plant Expansion 32 MGD Blue = Expansion; Green = Rehab 6

7 Rehab of Olathe Water Plant Facility Assessment, Membrane Rehab, Filter Rehab Lime Feed and Basin Rehabilitation Alternative Disinfection Chemical Feed Rehab Electrical Rehab Remote Facilities Rehab Blue = Expansion; Green = Rehab 7

8 Olathe Population Growth

9 Finished Water Meter Set-up

10 Flow (MGD) Difference (MGD) Primitive Testing " Mag Meter Comparison /9/13 11:36:00 AM 5/9/13 1:24:00 PM 5/9/13 3:12:00 PM 5/9/13 5:00:00 PM 5/9/13 6:48:00 PM 5/9/13 8:36:00 PM Time Membrane High Service 42" Magmeter Ave Diff (MGD)

11 Finished Water Meter Testing - Planning Select testing method No existing test ports Ability to isolate individual meters Repeatable by internal staff Develop testing plan Volumetric Test (Drawdown)

12 Finished Water Meter Testing - Planning

13 Finished Water Meter Testing 3 different 3 different flow rates Test - Thursday, October 20, 2016 Low Flow Rate Clearwell Test Meter Wetwell Starting Level feet Meter Reading: Starting Level feet Ending Level feet Time Start: 10:55 AM Ending Level feet Pump Flow: 2 MGD Total Volume 2,523 cubic feet Time End: 11:10 AM Total Volume 272 cubic feet MG Meter Reading: MG Meter Volume: MG Clearwell Wetwell Starting Level feet Meter Reading: Starting Level feet Ending Level feet Time Start: 11:10 AM Ending Level feet Pump Flow: 2 MGD Total Volume 2,613 cubic feet Time End: 11:25 AM Total Volume 290 cubic feet MG Meter Reading: MG Meter Volume: MG Clearwell Wetwell Starting Level feet Meter Reading: Starting Level feet Ending Level feet Time Start: 11:25 AM Ending Level feet Pump Flow: 2 MGD Total Volume 2,912 cubic feet Time End: 11:40 AM Total Volume 272 cubic feet MG Meter Reading: MG Meter Volume: MG Clearwell Wetwell Starting Level feet Meter Reading: Starting Level feet Ending Level feet Time Start: 11:40 AM Ending Level feet Pump Flow: 2 MGD Total Volume 2,722 cubic feet Time End: 11:55 AM Total Volume 279 cubic feet MG Meter Reading: MG Meter Volume: MG Test Total: MG Test Total: MG Test Total: MG Test Total - Tank Volume: MG (clearwell + wetwell) Test Total - Meter Volume: MG Difference: (0.008) MG UNDER REGISTRATION (7, ) -9.27%

14 SCADA data collection Manual level readings before/after Finished Water Meter Testing

15 Finished Water Meter Testing Results 42" Mag Flow Range Flow (MGD) Test Time Results % of Normal Flow Weighting Low 4 0: % OVER REGISTRATION 2% 0.00% Avg. 7 1: % OVER REGISTRATION 64% 0.88% High 10 0: % OVER REGISTRATION 34% 0.64% Composite Error Adjustment 1.53% OVER REGISTRATION 30" Mag Flow Range Flow (MGD) Test Time Results % of Normal Flow Weighting Low 1 0: % OVER REGISTRATION 9% 1.45% Avg. 3 1: % OVER REGISTRATION 88% 7.92% High 4 0: % OVER REGISTRATION 3% 0.31% Composite Error Adjustment 9.69% OVER REGISTRATION 24" Mag Flow Range Flow (MGD) Test Time Results % of Normal Flow Weighting Low 2 1: % UNDER REGISTRATION 73% -6.73% Avg : % UNDER REGISTRATION 18% -2.27% High 3 1: % UNDER REGISTRATION 9% -1.45% Composite Error Adjustment % UNDER REGISTRATION Water Balance Impacts Water Produced Volume MG/Yr MMEA % of Total Flow Weighting 42" Mag 2, % 67.84% 1.04% 30" Mag % 20.34% 1.97% 24" Mag % 11.83% -1.24% Composite Error Adjustment 1.77% OVER REGISTRATION

16 Meter Replacement Sizing o Manufacturer modeled flows o Checked 3 sizes (12, 18, 24 ) o Selected based on maximum flow

17 Meter Replacement Planning o o o Existing vault already in place 6 diameters upstream, 4 diameters downstream No as-builts. New Materials

18 24 Meter Replacement o o o o Piping had been retrofit previously 3 different pipe diameters Leaking valves New flushing assembly

19 30 Meter Replacement No Valve!! No Valve!!

20 Improvement? Ammonia Dosage Before (Difference 0.6 mg/l) Ammonia Dosage After (Difference 0.1 mg/l)

21 More Unmetered Unbilled Consumption No Meter for Plant Consumption?

22 Wrap Up o Procedure being updated to perform testing annually o Inexpensive way to validate reported flow o Plan installations for accuracy and maintenance!

23 Testing Finished Water Meters A Low Tech Approach John Gilroy, PE City of Olathe, Kansas jpgilroy@olatheks.org 12/5/2017