04/12/2023 - Packet
WATER ADVISORY BOARD AGENDA – April 12, 2023
City of Tigard | 8777 SW Burnham St., Tigard, OR 97223 | 503-718-2688 | www.tigard-or.gov | Page 1 of 2
City of Tigard Water Advisory Board Agenda
SERVING TIGARD WATER SERVICE AREA
MEETING DATE: Wednesday, April 12, 2023, 5:30 p.m.
MEETING LOCATION: 10 mil Conference Room - PW
Public Dial-in Number for listen-only phone bridge (971) 256-0577
When prompted enter Conference ID 13125
1. Call to Order, Roll Call, and Introductions
2. Approval of Minutes – February 8, 2023
Action: Motion to approve the February 8, 2023, minutes.
3. Public Comments
Call for comments from the public.
4. Water Supply Update –Sammy Rico
5. Reservoir 18 Update & Outreach Update – Shasta Billings-Beck
6. US EPA Lead and Copper Rule & AMI Meters – Ross Horton
7. Non-Agenda Items
Call for non-agenda items from the board.
8. Next Meeting
June 14, 2023
Location: 10 mil PW
Time: 5:30 pm
WATER ADVISORY BOARD AGENDA – April 12, 2023
City of Tigard | 8777 SW Burnham St., Tigard, OR 97223 | 503-718-2688 | www.tigard-or.gov | Page 2 of 2
The City of Tigard tries to make all reasonable modifications to ensure that people with disabilities have an equal
opportunity to participate in all city meetings.
Upon request, the city will do its best to arrange for the following services/equipment:
Assistive listening devices.
Qualified sign language interpreters.
Qualified bilingual interpreters.
Because the city may need to hire outside service providers or arrange for specialized equipment, those requesting
services/equipment should do so as far in advance as possible, but no later than 3 city workdays prior to the meeting.
To make a request, call 503-718-2591 (voice) or 503-684-2772 (TDD - Telecommunications Devices for the Deaf).
9. Adjournment
Action: Motion for adjournment.
Executive Session
The Water Advisory Board may go into Executive Session. If an Executive Session is called to order, the
appropriate ORS citation will be announced identifying the applicable statute. All discussions are confidential
and those present may disclose nothing from the Session. Representatives of the news media are allowed to
attend Executive Sessions, as provided by ORS 192.660(4), but must not disclose any information discussed.
No Executive Session may be held for the purpose of taking any final action or making any final decision.
Executive Sessions are closed to the public.
Water Advisory Board Water Supply Update
February 2023 Update
Tigard Usage
Current
(Feb 23)
Prior Yr
(Feb 22)
Avg Daily Use (MGD)4.28 4.02
Avg Temp 48°51°
Peak Use (MGD)4.58 4.25
Peak Temp 57°67°
Tigard Storage
Stored Water (ASR)344.1 203.9
Days of Supply 192.9 111.8
4.28
Average
4.00
3.4
3.5
3.6
3.7
3.8
3.9
4
4.1
4.2
4.3
4.4
Average Daily Demand (ADD)
0
20
40
60
80
100
120
140
0
2
4
6
8
10
12
14
Jul 2020Aug 2020Sep 2020Oct 2020Nov 2020Dec 2020Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023TemperatureMillion Gallons Per Day (MGD)Tigard Usage and Air Temperature Over Time
Peak Temperature Average Temperature Average Daily Use (MGD)Peak Use (MGD)
February Usage
Average daily water use for the month of February was 4.28
million gallons per day (mgd). Peak daily use was 4.58 mgd.
Last year, average daily water use was 4.02 mgd for the same
time period, with a peak day of 4.25 mgd. Both the average
daily use and peak demand for February were above the
historic averages of 4.00 mgd and 4.41 mgd respectively.
4.58Peak4.41
0
1
2
3
4
5
6
Peak Daily Demand (PDD)
The chart above shows Tigard's average daily water use for the current fiscal year (YTD), as well as two years
prior. This usage is compared to the average and peak air temperatures during that time, displayed as the colored
area. This shows the seasonality of water consumption and the close relationship with temperature.
Water Advisory Board Water Supply Update
Stored Water (ASR)
Lake Oswego-Tigard Water Treatment Plant & Bonita Pump Station
Data Metrics
Current
(Feb 23)
Prior Yr
(Feb 22)
Chlorine Residual 1.13 1.17
Alkalinity 23.66 22.83
pH 7.82 7.76
Temperature 6.02 6.73
0
50
100
150
200
250
0
50
100
150
200
250
300
350
400
Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Days of SupplyStored Water (MG)Stored Water (ASR)
ASR #1 ASR #2 Days of Supply
The chart above shows Tigard's current stored water (ASR levels) as well as 12 months of prior histoy.
The storage levels of ASR #1 and ASR #2 are stacked to show total combined stored water. The days
of supply, based on the amount of stored water, is displayed on the right axis and as the gray line.
0
0.5
1
1.5
2
2.5
3
3.5
4
Chlorine Residual (0.2-4.0ppm boundary)Chlorine Residual: 1.13 ppm
Chlorine is a disinfectant used to
protect the public from virus,
bacteria, and other micro-
organisms. The maximum level
for chlorine in drinking water is 4
ppm and the minimum level
required is 0.2 ppm (indicated by
the yellow shaded area in the
chart above). The average
chlorine residual from July 2020
to current is 1.10 ppm.
Definitions:
LOTWTP:Lake Oswego-Tigard Water Treatment Plant
mg/L:millograms per liter, also expressed as ppm
ppm: parts per million, a measurement of the mass of a
chemical per unit volume of water.
cfs: cubic feet per second, measurement of rate of flow
Water Advisory Board Water Supply Update
0
10
20
30
40
50
60
70 Finished Water Alkalinity (ppm)
4
5
6
7
8
9
10
pH (Raw & Finished)
Clackamas River pH Bonita pH Neutral
0
5
10
15
20
25
Water Temperature C (Raw & Finished)
Clackamas River LOTWTP
Alkalinity: 23.66 ppm
Alkalinity is water's capacity
(buffering) to resist acidic
changes in pH or to neutralize
acid. A normal range for
alkalinity in finished drinking
water is 20-200 mg/L (indicated
by the blue shaded area). The
EPA Secondary Drinking Water
Regulations limit alkalinity only
in terms of total dissolved solids
not to exceed 500ppm.
pH: 7.82
pH is a numerical measure of
the acidity or alkalinity (base) of
a solution, measured on a scale
of 0 to 14. Neutral on the scale
is 7 (indicatd by the gray line in
the chart), below 7 is acidic and
above 7 is alkaline. For drinking
water, slighly base chemistry
(alkaline) provides anti-
corrosion properties to protect
water supply plumbing and
reduces the risks associated
with lead solder and copper
plumbing.
Water Temperature:6.02C
(43F)
While water temperature can
have a major influence on
biological activity and organic
life in bodies of water, there is
not an EPA standard for the
temperature of finished
drinking water.
As you can see in the chart
above, the temperature of the
finished drinking water
fluctuates in tandem with the
temperature of the source water
(Clackamas River).
Water Advisory Board Water Supply Update
USGS Clackamas River Water Data
The following charts contain U.S. Geological Survey data collected from the Clackamas River. The charts on this
page show a comparison of the current month of data to that same month in the prior years, as well as an average
over those years. On the second page, those charts show the historical trends of each metric from July 2011 to
current. Turbidity, a metric not yet defined in this report, is the relative clarity of a liquid. It is an optical
characteristic, measuring the amount of light scattered by material in the water, measured in nephelometric
turbidity units (NTU).
4.9
Average, 5.7
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Temperature for Current Month
2432.9
Average, 5,051
0
2,000
4,000
6,000
8,000
10,000
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Flow for Current Month
7.6
6.6
6.8
7.0
7.2
7.4
7.6
7.8
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
pH for Current Month
2.2
Average, 4.1
0.0
2.0
4.0
6.0
8.0
10.0
12.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Turbidity for Current Month
Water Advisory Board Water Supply Update
0
2
4
6
8
10
12
14
16
18
20
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Turbidity of Clackamas River (NTUs)
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
pH of Clackamas River
0
2,000
4,000
6,000
8,000
10,000
12,000
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Discharge (Flow) of Clackamas River (cfs)
0
5
10
15
20
25
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Temperature of Clackamas River (c)
Water Advisory Board Water Supply Update
March 2023 Update
Tigard Usage
Current
(Mar 23)
Prior Yr
(Mar 22)
Avg Daily Use (MGD)4.18 4.11
Avg Temp 53°57°
Peak Use (MGD)4.36 4.36
Peak Temp 68°67°
Tigard Storage
Stored Water (ASR)344.1 278.5
Days of Supply 192.9 154.0
4.18Average
4.04
3.4
3.6
3.8
4
4.2
4.4
4.6
Average Daily Demand (ADD)
0
20
40
60
80
100
120
140
0
2
4
6
8
10
12
14
Jul 2020Aug 2020Sep 2020Oct 2020Nov 2020Dec 2020Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023TemperatureMillion Gallons Per Day (MGD)Tigard Usage and Air Temperature Over Time
Peak Temperature Average Temperature Average Daily Use (MGD)Peak Use (MGD)
March Usage
Average daily water use for the month of March was 4.18
million gallons per day (mgd). Peak daily use was 4.36 mgd.
Last year, average daily water use was 4.11 mgd for the same
time period, with a peak day of 4.36 mgd. Average daily use
for March was above the historic average of 4.04 mgd, but
peak demand was below the historic average of 4.47 mgd for
the month.
4.36
Peak 4.47
0
1
2
3
4
5
6
Peak Daily Demand (PDD)
The chart above shows Tigard's average daily water use for the current fiscal year (YTD), as well as two years
prior. This usage is compared to the average and peak air temperatures during that time, displayed as the colored
area. This shows the seasonality of water consumption and the close relationship with temperature.
Water Advisory Board Water Supply Update
Stored Water (ASR)
Lake Oswego-Tigard Water Treatment Plant & Bonita Pump Station
Data Metrics
Current
(Mar 23)
Prior Yr
(Mar 22)
Chlorine Residual 1.07 1.16
Alkalinity 23.26 20.77
pH 7.93 7.94
Temperature 7.11 8.66
0
50
100
150
200
250
0
50
100
150
200
250
300
350
400
Jan 2021Feb 2021Mar 2021Apr 2021May 2021Jun 2021Jul 2021Aug 2021Sep 2021Oct 2021Nov 2021Dec 2021Jan 2022Feb 2022Mar 2022Apr 2022May 2022Jun 2022Jul 2022Aug 2022Sep 2022Oct 2022Nov 2022Dec 2022Jan 2023Feb 2023Mar 2023Days of SupplyStored Water (MG)Stored Water (ASR)
ASR #1 ASR #2 Days of Supply
The chart above shows Tigard's current stored water (ASR levels) as well as 12 months of prior histoy.
The storage levels of ASR #1 and ASR #2 are stacked to show total combined stored water. The days
of supply, based on the amount of stored water, is displayed on the right axis and as the gray line.
0
0.5
1
1.5
2
2.5
3
3.5
4
Chlorine Residual (0.2-4.0ppm boundary)Chlorine Residual: 1.07 ppm
Chlorine is a disinfectant used to
protect the public from virus,
bacteria, and other micro-
organisms. The maximum level
for chlorine in drinking water is 4
ppm and the minimum level
required is 0.2 ppm (indicated by
the yellow shaded area in the
chart above). The average
chlorine residual from July 2020
to current is 1.10 ppm.
Definitions:
LOTWTP:Lake Oswego-Tigard Water Treatment Plant
mg/L:millograms per liter, also expressed as ppm
ppm: parts per million, a measurement of the mass of a
chemical per unit volume of water.
cfs: cubic feet per second, measurement of rate of flow
Water Advisory Board Water Supply Update
0
10
20
30
40
50
60
70 Finished Water Alkalinity (ppm)
4
5
6
7
8
9
10
pH (Raw & Finished)
Clackamas River pH Bonita pH Neutral
0
5
10
15
20
25
Water Temperature C (Raw & Finished)
Clackamas River LOTWTP
Alkalinity: 23.26 ppm
Alkalinity is water's capacity
(buffering) to resist acidic
changes in pH or to neutralize
acid. A normal range for
alkalinity in finished drinking
water is 20-200 mg/L (indicated
by the blue shaded area). The
EPA Secondary Drinking Water
Regulations limit alkalinity only
in terms of total dissolved solids
not to exceed 500ppm.
pH: 7.93
pH is a numerical measure of
the acidity or alkalinity (base) of
a solution, measured on a scale
of 0 to 14. Neutral on the scale
is 7 (indicatd by the gray line in
the chart), below 7 is acidic and
above 7 is alkaline. For drinking
water, slighly base chemistry
(alkaline) provides anti-
corrosion properties to protect
water supply plumbing and
reduces the risks associated
with lead solder and copper
plumbing.
Water Temperature:7.11C
(45F)
While water temperature can
have a major influence on
biological activity and organic
life in bodies of water, there is
not an EPA standard for the
temperature of finished
drinking water.
As you can see in the chart
above, the temperature of the
finished drinking water
fluctuates in tandem with the
temperature of the source water
(Clackamas River).
Water Advisory Board Water Supply Update
USGS Clackamas River Water Data
The following charts contain U.S. Geological Survey data collected from the Clackamas River. The charts on this
page show a comparison of the current month of data to that same month in the prior years, as well as an average
over those years. On the second page, those charts show the historical trends of each metric from July 2011 to
current. Turbidity, a metric not yet defined in this report, is the relative clarity of a liquid. It is an optical
characteristic, measuring the amount of light scattered by material in the water, measured in nephelometric
turbidity units (NTU).
6.0
Average, 6.9
0.0
2.0
4.0
6.0
8.0
10.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Temperature for Current Month
2940.6
Average, 5,267
0
2,000
4,000
6,000
8,000
10,000
12,000
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Flow for Current Month
7.7
6.8
7.0
7.2
7.4
7.6
7.8
8.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
pH for Current Month
3.6
Average, 4.2
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
Turbidity for Current Month
Water Advisory Board Water Supply Update
0
2
4
6
8
10
12
14
16
18
20
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Turbidity of Clackamas River (NTUs)
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
pH of Clackamas River
0
2,000
4,000
6,000
8,000
10,000
12,000
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Discharge (Flow) of Clackamas River (cfs)
0
5
10
15
20
25
Jul
2011
Jan
2012
Jul
2012
Jan
2013
Jul
2013
Jan
2014
Jul
2014
Jan
2015
Jul
2015
Jan
2016
Jul
2016
Jan
2017
Jul
2017
Jan
2018
Jul
2018
Jan
2019
Jul
2019
Jan
2020
Jul
2020
Jan
2021
Jul
2021
Jan
2022
Jul
2022
Jan
2023
Temperature of Clackamas River (c)
Reservoir 18 and Pump StationWater Advisory Board Update –April 12, 2023
Agenda1. Happenings since August 20222. What’s on the Horizon3. Schedule4. General Q/A
Sept. 2022•30% design and cost estimate received, reviewed, and returned•410 pressure zone piping deficiencies were identified during hydraulic modeling•Upsizing of existing pipes would be necessary for Pump Station 13 to be a reliable source for Reservoir 18•Land Use applications submitted
Oct. 2022•Piping supplier was added to PDB team•Mitigated risk of cost increase and allowed project to be placed in production cue, which alleviates delivery timeline concerns•Temporary construction easement (TCE) signed by White family•Installation of Roshak Ridge PRV began
Nov. 2022•Amendment for design of 410 piping improvements approved by Council•Site 13 Land Use approved•60% design and cost estimate received at end of month•Roshak Ridge PRV online
Dec. 2022•60% design and cost estimate reviewed and returned•Emery performed extensive potholing work along piping routes to assist with design fine‐tuning•50% design for 410 piping improvements received
Jan. 2023•Hearing for Reservoir 18 Conditional Use Permit and Sensitive Lands Review completed –no comments received•Land Use for Reservoir 18 approved•GMP negotiations began•Team elected to bid out reservoir sub package to mitigate risk to GMP
Feb. 2023•Tank contractor bid opening•Marion Construction determined lowest responsible bidder•GMP negotiations finalized•Erosion control permits applied for
March 2023•GMP amendment presented to Council 3/7 and approved 3/14•$28,987,700•90% design received and reviewed•Site 13 PFI permit applied for
April 2023•90% design reviewed and returned•Amendment issued to Kennedy Jenks (Owner’s Rep) to provide construction oversight services•Reservoir 18 PFI permit applied for•CAC meeting 4/19•Will review renderings for site following construction•Will discuss construction timeline
On the Horizon: Spring 2023•Neighborhood meetings•Equipment to be delivered to Sunrise Park in Spring 2023•100% For Construction drawings to be received and reviewed•Construction will begin following permit issuance
Current ScheduleReservoir 18•Mass excavation Spring to Fall 2023(Sunrise closed)•Tank Construction Fall 2023 –Fall 2024(Limited park access)•Backfill & testing Fall 2024 –Winter 2025(Sunrise closed)•Tank online Winter 2025Pump Station 13•Construction Spring 2023 –Fall 2024•Pump Station Online Winter 2025(delayed due to generator and transformer availability)Offsite Piping•Construction Summer 2023 – Summer 2024
Questions?
CITY OF TIGARDRespect and Care | Do the Right Thing | Get it DoneTigard Water Advisory BoardAMI Water Meter Pilot Program &US EPA Lead & Copper Rule RequirementsApril 12, 2023PW Engineering
CITY OF TIGARDAgendaAdvanced Metering Infrastructure (AMI) Water Meter Pilot ProgramUS EPA Lead and Copper Rule Revisions (LCRR)
CITY OF TIGARDAMI Water Meter Pilot ProgramAutomated Meter Reading (AMR) Meters currently installed throughout TWSAAdvanced Meter Infrastructure (AMI) Meters are new standard & provide increased level of serviceAMR AMIRecording Frequency Daily HourlyRead Frequency ~Monthly DailyMeter Resolution 100 CF (750 Gal) 1 CF (7.5 Gal)Receiver Type Drive‐By Radio LoRa WANCustomer Interface None Online
CITY OF TIGARDAMI Water Meter Pilot ProgramMeter Route 31Residential & Commercial248 Meters replaced (in process)Install new LoRa WAN Radios (April‐June)
CITY OF TIGARDAMI Water Meter Data CollectionMeter read data routed through manufacturer serverMeters analyzed for customer‐side leaks/suspicious usageData imported to Utility Billing system
CITY OF TIGARDLoRa WAN Wireless TechnologyWidely used in Europe & South AmericaIndependent sensors & long battery lifePowers the “Internet of Things” and enables “Smart City”LightingTraffic SignalsParkingAsset Monitoring
CITY OF TIGARDAMI Water Meter Pilot Program GoalsLearn how to integrate new data management/AMI meter reads into Utility Billing softwareDetermine how to integrate AMI meter reads with Total TylerDetermine how customers can access AMI meter dataProof‐test LoRa WAN technology for other City uses
CITY OF TIGARDQuestions/Comments?
CITY OF TIGARDLead Health EffectsLead is a highly toxic pollutant that can damage neurological, cardiovascular, immunological, developmental, and other major body systems.No safe level of lead exposure has been identified, and it is especially harmful to children and pregnant women.Bans: Gasoline for passenger cars: 1975Paint for residential use: 1978Gas for commercial vehicles: 1996Source: Oregon Health Authority
CITY OF TIGARDHistory: Lead & Copper RegulationEPA Rule published Lead and Copper Rule (LCR) in 1991Sets Maximum Contaminant Level Goals and Action Levels for lead and copperTigard currently samples for lead and copper as part of EPA and OHA testing complianceNo lead or copper found in Tigard water system above action levelsLead pipes generally not issue in our regionOregon banned lead pipes in 1985 for public water systems
CITY OF TIGARDLead & Copper Rule RevisionsEPA LCR Revisions (LCRR) adopted in 2021Lowers Trigger Level for remedial actionsIncreases sampling requirements for schools and childcare centersRequires creation of inventory for all service lines Requires public notification regarding status of any service line that has potential to be lead, and a plan for replacement
CITY OF TIGARDLCRR InventoryWhat is a Service Line (SL)?“Public” SL “Private” SLSource: US EPA
CITY OF TIGARDLCRR InventoryIdentify all SLs and their material for all customersLeadNon‐Lead (copper, plastic, galvanized, iron)Galvanized Requiring Replacement (GRR)UnknownTigard water service area has ~41,000 service linesEvidence‐based identification requiredRecords review, visual inspection, excavation, predictive modeling/statistical samplingSubmit to Oregon Health Authority by October 2024
CITY OF TIGARDTigard Action Plan –What we KnowNO known Lead Service Lines (LSLs)Public SLs installed after 1974 are copper (<=2”) or iron (>2”)Unknown SL material on private side of water meterSLs installed pre‐1986 are unknown material, potentially lead, and require identificationSLs installed 1986 and later considered non‐lead even if material unknownSLs 2‐inches and larger considered non‐lead
CITY OF TIGARDTigard Action Plan – Preliminary InventoryDevelop initial inventory –Completed March 2023Reviewed •Tax lot information•Historical engineering standards•Development plans•Maintenance recordsMany unknown SLs •4,398 unknown public SLs•7,827 unknown private SLsNo known LSLs
CITY OF TIGARDTigard Action Plan –Statistical ModelOHA allows statistical model to verify no LSLs in inventoryPhysically verify sub‐set of unknown SLsModel will prove with 95% confidence absence of LSLs
CITY OF TIGARDTigard Action Plan – Field InvestigationsTigard PW field crews to complete physical investigations367 randomly selected locations with “unknown” SL materialPhysically verify SL materials inside water meter box with vacuum excavator – minimally invasiveRecord SL material entering (public) and exiting (private) water meter boxResults recorded with Tigard Maps interface
CITY OF TIGARDTigard Action Plan – Finalize InventoryVerify no LSLs with statistical model – Spring 2024If no LSLs found during field investigations, 95% confident that no LSLs in Tigard water system, meets OHA requirementsIf LSLs are found, work with OHA to develop LSL replacement plan & evaluate required field investigationsComplete OHA inventory template – Spring/Summer 2024Goal = no unknowns in inventorySubmit by October 2024
CITY OF TIGARDTigard Action Plan – Public EngagementPublic Notifications – Summer 2024No LSLs & no unknowns; Statement certifying no LSLs in Tigard water system•Posted to Tigard PW website•No public inventory requiredLSLs present, or unknowns in inventory•Notification to customers with LSLs, GRRs, or Unknown SL•Publicly accessible SL inventory via Tigard Maps interface•Inventory must be updated annually
CITY OF TIGARDLSL Replacement PlanHopeful that Tigard water system will be “lead free” based on physical investigations & statistical modelingIf required, prepare LSL replacement plan – Summer/Fall 2024Statistical model invalid if any LSLs foundTotal number of LSLs would be very smallWould require •Work closely with OHA to prepare approved plan•Large effort to identify remaining unknown SLs
CITY OF TIGARDQuestions/Comments?