Workshop A: Wauwatosa's I&I Challenges and Successes Bill Wehrley and Chris Samborski

7/30/2019 Workshop A: Wauwatosa's I&I Challenges and Successes Bill Wehrley and Chris Samborski

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Wauwatosas I&I Challengesand Successes

Chris Stamborski, P.E. R.A. Smith National, Inc.

Bill Wehrley, P.E. City of Wauwatosa

April 25, 2013


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City of Wauwatosa - Honey Creek Study Area History

MMSD Indicated Honey Creek study area exceeded the PeakWet Weather Flow Performance Standards

City Performed LSSES that included:

Sanitary SewerManholeInspections

Sanitary SewerTelevising andNASSCOPipelineConditionAssessment

Smoke Testing

Sanitary SewerFlow Monitoring


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Honey Creek LSSES Conclusions

Flow Monitoring data indicated which areas of the HoneyCreek were reporting high flows Results of the manhole inspections, smoke testing, and standard CCTV

work did not account for the quantity of clear water that was enteringthe system

Honey Creek studyarea wasprioritized basedon results of

LSSES study

Recommendationswere given toaddress structuraldeficiencies inPublic Sector

system and lookfurther into waysto identifyclearwater entryfrom the PrivateSector


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Flow Monitoring data indicated which areas of the Honey Creek werereporting high flows

Results of the manhole inspections, smoke testing, and standard CCTV work didnot account for the quantity of clear water that was entering the system

Honey Creek study area was prioritized based on results of LSSESstudy

Recommendations were given to address structural deficiencies inPublic Sector system and look further into ways to identify clearwaterentry from the Private Sector

City chose to perform surcharge dyewater testing of the storm sewer withinhigh flow areas in an attempt to identifysources of clearwater entry into thesanitary sewer system

Honey Creek LSSES Conclusions


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Dye Water Flooding Overview

Traditional practice that hasproven to be an effective

method for a variety ofpurposes

In this practice, dye floodingis performed in conjunction

with CCTV to confirmpotential I/I sources thatwere identified as part ofother investigation methods

Dye water flooding aids in

verifying both the presenceand quantification of specificdefects during an evaluation


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Dye Water Flooding Overview (cont.)


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City of Wauwatosa Dye Flooding Project Examples

The following areexamples of standardCCTV performed as part

of the 2008 LSSESproject shown side-by-side with 2010 CCTV workdone with the dyeflooding project in theCity of Wauwatosa


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Example: Clay Riser Lateral Leaking

2008 Standard CCTV 2010 Dye Flood CCTV


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Example: Laterals Leaking after Relay of Entire Mainline Sewer



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Example: Mainline Joints and Lateral Leaking in Segmental PVC Relay



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Example: Lateral Leaking Adjacent to Storm Sewer CIPP Reline



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Dye Water Flooding Discharge


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Honey Creek Study Area Dye Water Flooding Results

Approximately 80% of lateralscrossing mainline storm sewer

pipe had dye water witnessed

Approximately 974 gallons perminute of dyed water entering thesanitary sewer system Public 204 gpm (21%)

Private 770 gpm (79%)

Recommended Solutions Sanitary Sewer Lateral Rehabilitation

all the way to the foundation of thehouse

Sewer Manhole and MainlineRehabilitation

Need to be performed concurrently


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Phase III Dye Testing for the City of Wauwatosa

Work Completed for

City in Fall 2010

~ 11,000 SanitarySewer CCTV withStorm Sewer DyeFlooded

~ 1,300 GPM Leaks 16% from Public

84% from Private


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Phase IV Dye Testing for City of Wauwatosa

Work Completed forCity in Spring 2011

~ 70,000 SanitarySewer CCTV with

Storm Sewer DyeFlooded

~ 5,800 GPM Leaks 28% from Public

72% from Private


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Watertown Plank Road Area Dye Testing for City of Wauwatosa

Work Completed forCity in Summer2011

~ 40,000 Sanitary

Sewer CCTV withStorm Sewer DyeFlooded

~ 1,120 GPM Leaks

38% from Public

62% from Private


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WA4004 Sewershed Dye Testing for City of Wauwatosa

Work Completed forCity in Summer2011

~ 14,000 Sanitary

Sewer CCTV withStorm Sewer DyeFlooded

~ 234 GPM Leaks

25% from Public

75% from Private

D W t Fl di C l i


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Dye Water Flooding Conclusions

Standard CCTV is very useful to determine the condition of theexisting sewer lines, but does not always show what is happeningduring high flow events

CCTV with dye water flooding will show where leaks are presentduring a simulated storm event

Majority of clear water that leaves the storm system and enters the

sanitary system does so through private laterals

Presence of storm laterals provides more exit and entry points formigration of water between storm system and sanitary systemthrough laterals and common trenches

Knowing where the leaks are located in your system will assist indetermining the most cost-effective means to reduce clearwaterentry into the system

City of Milwaukee | Environmental Engineering


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QUESTIONS???

City of Milwaukee | Environmental Engineering

Documents

Workshop A: Wauwatosa's I&I Challenges and Successes Bill Wehrley and Chris Samborski