Embed Size (px)
Citation preview
© 2013 ARCADIS19 June 20131
History Repeats Itself–The City of Columbus’ Water in
Basement Mitigation Assessment
Muralikrishna Chelupati – ARCADISC. Timothy Fallara, P.E. – City of Columbus
Mike Foster – City of ColumbusDr. Hazem Gheith, P.E. – ARCADISLaura McGinnis, P.E. – ARCADIS
87th Ohio Water Environment Association Annual ConferenceJune 19, 2013Mason, Ohio
© 2013 ARCADIS19 June 20132
What are WIBs?
http://www.mosbybuildingarts.com/blog/2011/04/21/preventing-sewer-back-up/
© 2013 ARCADIS19 June 20133
• Tracking of WIBs affected by WWMP related projects
• Make informed decisions on I/I projects• Evaluate effectiveness of I/I programs• Better allocate O&M resources
Why is Columbus
undertaking this study?
© 2013 ARCADIS19 June 20134
Topics Background and Goals
Approach
Results
Benefits
© 2013 ARCADIS19 June 20135
City of Columbus Collection System
© 2013 ARCADIS19 June 20136
Columbus’ WIB Complaint Tracking
Customer calls with
WIB complaint
Columbus documents WIB complaints in a
database
Field crews complete a site
visit to investigate
Probable responsibility determined
Findings documented in a database
© 2013 ARCADIS19 June 20137
• Completed in 2009• Evaluated WIB records from 2002 – 2005• Only City responsible WIBs considered• 1400 WIBs evaluated • Identified I/I remediation projects
necessary to mitigate areas unaffected by WWMP projects
Phase I Study
Recommendations from Phase I Study:• Begin implementing I/I remediation projects • Analyze more years of data (all WIBs, not just City responsibility)
• Analyze trends• Further define problem areas• Evaluate project effectiveness
© 2013 ARCADIS19 June 20138
Phase II Study Goals
Provide Columbus with data trends to:
Prioritize I/I remediation
projects
Identify potential
maintenance issues
Evaluate the effectiveness of
O&M and I/I remediation
projects
Define repeatable process for future studies
Evaluate WIB complaints 2002 – 201013,282 WIB records
© 2013 ARCADIS19 June 20139
Topics Background and Goals
Approach
Results
Benefits
© 2013 ARCADIS19 June 201310
Phase II Study ApproachClassify rainfall influenced WIB complaints
Identify potential clusters
Prioritize clusters
Assess potential reasons for WIB complaints
© 2013 ARCADIS19 June 201311
Developing an Approach to Classify WIBs was Challenging…
© 2013 ARCADIS19 June 201312
Final Approach to Classify WIB ComplaintsA WIB complaint would be considered ‘wet’ if
rainfall fell on any of the two preceding days or if at least 2.0 inches of rain fell on the third preceding day.
June 16
0.85”
June 17
0.45”
June 18
0”
June 19
0”
June 20
0”
Wet DryWet
© 2013 ARCADIS19 June 201313
Spatial Distribution of Rain Gauge Data
© 2013 ARCADIS19 June 201314
WIB Complaint Data
© 2013 ARCADIS19 June 201315
Using that criteria:Final WIB Complaint
Classification Total WIBs13,282
Wet WIBs10,558
Dry WIBs2,724
© 2013 ARCADIS19 June 201316
Wet vs. Dry WIB Complaints
© 2013 ARCADIS19 June 201317
• To prioritize future I/I remediation projects, we need to find the “hot spots”
• Group WIB complaints to define clusters Ignore dry WIBsEvaluate hydraulically connected WIBs
Identifying Potential Clusters
http://www.notoriousspinks.com/2011/01/02/30-day-road-to-discovery-day-1-self-evaluation/confused/
© 2013 ARCADIS19 June 201318
Sample Cluster
© 2013 ARCADIS19 June 201319
• How to prioritize 227 clusters to assist Columbus with I/I CIPs?
• After much discussion:Develop
Criteria to Prioritize Clusters
Frequency
Criteria 1Total number of WIB complaints
Criteria 4Total number of
recent WIB complaints
Density
Criteria 2WIB complaint
density per acreage
Criteria 3WIB complaint
density per parcel count
© 2013 ARCADIS19 June 201320
Scenario No.
Criteria 1 – Total # of Wet WIBs
Criteria 2 – WIB
Density per Area
Criteria 3 – WIB
Densityper
Parcel
Criteria 4– Total #
of Recent WIBs
No. 1 – Equal Weighting
33% 33% 33%
No. 2 – Equal Weighting Including Recent WIB Complaints
25% 25% 25% 25%
No. 3 - Higher Weighting on Recent WIB Complaints
20% 20% 20% 40%
• And more discussion on various methods to rank clusters:
© 2013 ARCADIS19 June 201321
Scenario 2 vs. Scenario 3
© 2013 ARCADIS19 June 201322
Assess the potential
reason for WIB
complaints
• Existing Sanitary Sewer Capacity Model used to evaluate potential capacity constraints
• Field investigations still required
Did limited capacity create WIBs?
Is the cause just unknown?
Did roots cause a backup?
© 2013 ARCADIS19 June 201323
SSCM Model Plan
& Profile
© 2013 ARCADIS19 June 201324
What can the model
tell us?
• If the model does predict surcharge
• Indication of surcharge does not directly correlate to WIB complaints, rather surcharge may be one of the many more complex reason for WIB complaints
• If the model does not predict surcharge
• No apparent reason and additional investigations are recommended
© 2013 ARCADIS19 June 201325
Topics Background and Goals
Approach
Results
Benefits
© 2013 ARCADIS19 June 201326
Prioritized Clusters
© 2013 ARCADIS19 June 201327
Very High Cluster
• Why?Wet WIB per AreaWet WIBs per ParcelRecent Wet WIBs
• Potential Reason?Surcharge
© 2013 ARCADIS19 June 201328
Very High Priority Cluster
• Why?Wet WIBs per AreaWet WIBs per ParcelRecent Wet WIBs - FAILED
• Recent lift station eliminated capacity issues
• Dropped from Very High to lesser priority
© 2013 ARCADIS19 June 201329
Topics Background and Goals
Approach
Results
Benefits
© 2013 ARCADIS19 June 201330
Benefits • Now that the WIB complaint data is processed, what else can we do with it?
Look at yearly or monthly trendsEvaluate impact of sewer cleaning
on WIBsAssess severity during specific
rainfall eventsEstimate impact of sewer
modifications on potential WIB complaints
© 2013 ARCADIS19 June 201331
Analyze Trends
© 2013 ARCADIS19 June 201332
Sewer Cleaning Has a Positive Impact on WIB Complaints
II Study Area Cleaning Period
Total # Years WIB Data Available
WIB Complaints Per Inch of Rain
Before Cleaning After Cleaning Before
Cleaning After Cleaning
Barthman-Parsons
11/2007 –6/2010 5.3 0.5 2.2 1.7
Early Ditch Relief
6/2006 –9/2007 3.8 3.3 2.9 1.7
Livingston-James
5/2005 –7/2006 2.8 4.4 7.2 4.2
Miller-Kelton 9/2009 –11/2009 7.1 1.1 0.4 0.5
North West Alum Creek
9/2008 –10/2009 6.1 1.2 3.6 2.8
Plum Ridge 4/2010 –6/2010 7.7 0.5 0.1 0.2
West 5th Ave 3/2007 –11/2009 4.8 1.1 0.2 0.2
© 2013 ARCADIS19 June 201333
Event Specific WIB Data Supports On-Going Projects
How did a large event in 2005 impact this area?
Only three WIB complaints filed
© 2013 ARCADIS19 June 201334
What trends do we see over time?
Will the proposed large-scale CIP likely reduce WIBs?
WIBs are already trending down
Quickly Summarize WIB Complaints in Specific Areas to Support CIP
Duration TOTAL WIBs TOTAL DRY WIBs TOTAL WET WIBs2002 - 2004 1435 226 12092005 - 2006 1305 196 11092007 - 2008 1291 222 10692009 - 2010 874 258 616
Total 4905 902 4003
WIBs in ACT Meter Basins
© 2013 ARCADIS19 June 201335
Next Steps• WIB clusters with ‘Very High’ and
‘High’ priority designation will be considered a potential future I/I remediation project
• The remaining clusters will still aid the City in understanding where potential hydraulic constraints and/or maintenance issues may exist
• WIB data will continue to be evaluated as it is collected and to analyze trends and confirm priority areas
© 2013 ARCADIS19 June 201336
Conclusions • Impact of anticipated WWMP and CIP projects have not yet been evaluated in terms of mitigating WIBs
• Columbus has realized benefits of having the processed WIB data readily available to support other questions and projects
© 2013 ARCADIS19 June 201337
Questions?
http://www.mosbybuildingarts.com/blog/2011/04/21/preventing-sewer-back-up/
© 2012 ARCADIS19 June 201338
Imagine the resultC. Timothy Fallara, P.E.Sr. Project ManagerCity of Columbus, DPU, DOSD910 Dublin Road, 3rd Floor Columbus, OH 43215Tel : (614) [email protected]
Muralikrishna ChelupatiEnvironmental Engineer 2ARCADIS U.S.1100 Superior Ave, Suite 1250Cleveland, OH 44114Tel : (216) [email protected]
