Manhole Assessment & Rehabilitation MACP Provides Framework for Comprehensive Program Iowa Water Environment Association Collection System Specialty Conference March 9-11, 2011 - Marshalltown, Iowa Andrew L. Craven, P.E. Strand Associates, Inc Madison, WI
Presentation Overview Background Local Issues & Regulatory Requirements MACP Overview Fond du Lac Manhole Assessment Program Program development Field implementation Rehabilitation Program Development
City of Fond du Lac Population 43,600 French for foot of the lake Located on the southern end of Lake Winnebago
Walleye Weekend! Lake Winnebago is one of the largest inland lakes in the US Considered one of the top walleye fisheries in the nation Early June festival draws thousands to the Fond du Lac area
Fond du Lac Collection System 194 miles of sewer 6-inches to 48-inches 5,000+ manholes Oldest parts of the system are over 100 years old
Collection System Issues Foot of the lake = marsh! Storm sewer system pumped to lake City has historically experienced SSOs and WIB Accepted as statusquo!?
What Changed? New City staff no longer accepted wet weather operations as the statusquo! Wisconsin DNR included a requirement for an SSES in the City s WWTP permit City council provided long term funding for program
Wet Weather Game Plan Short Term Reduce HGL in collection system bypass pumping to storm sewer New WWTP influent pumping station significantly changed the operation of the collection system Free discharge @ WWTP
Wet Weather Game Plan Long Term SSES completed in 2004 Dedicated funding for clearwater program includes two full time staff Ongoing CCTV program with follow-up repairs
SSES Recommendations Identified $8 million in potential I/I related rehabilitation Worked with WDNR to establish a long-term rehabilitation program no quick-fix program. Instead long term commitment on behalf of City Recommended a manhole assessment & rehabilitation program
Manhole Assessment & Rehabilitation Multi-year program (4+) Year 1 (2009) 1,250± manholes assessed (25%) Year 2 Rehabilitation & Assessments
Manhole Assessment Options? Existing manhole assessment forms not detailed enough! No city program in place Create new program from scratch? Identify existing program?
NASSCO / MACP National Association of Sewer Service Companies Industry advocacy group involved with pipeline rehabilitation Develop industry specific standards, educational materials, etc. MACP Manhole Assessment & Certification Program PACP developed in 2001 pipeline assessment program Manholes are treated as vertical pipes MACPprovides a framework for assessing manhole condition Goal is uniformity!
MACP Overview Level 1 Inspection Provides basic information to assess the general condition of a manhole Level 2 Inspection Much more detailed Level 2 is required if you are going to make decisions regarding rehabilitation Forms are designed to take the user through the assessment. Goal Standardized process which results in uniformity of observations
Manhole Diagram
MACP Inspection Form
MACP Component Observation
MACP Defect Documentation
PACP Observation Codes
PACP Observation Codes
Project Forms We determined we did not need to collect all of the information contained in the NASSCO form What do we need to set up a rehab program? What additional information do we want to capture? Coordinated with City staff engineering & GIS
Project Specific Forms Fond du Lac Form 1 -General Information Many fields can be pre-populated and only need to be changed if conditions require
Project Specific Forms Fond du Lac Form 2 Manhole Components Form set up to take user from top to bottom of structure
Project Specific Forms Fond du Lac Form 3 Pipe Connections Did not gather elevation information this already exists in the City s GIS
Project Specific Forms Fond du Lac Form 4 Defects Room for 6 defects If more than 6 defects, it is likely the manhole should be replaced!
Field Assessment Procedure Tablet PC used to collect data 2 person crew top person responsible for PC Second person performs assessment and calls out observations Repetition created efficiencies 15-minutes per manhole (average) lots of info! No paper forms! No additional data entry!
Final Step Important! Overall manhole assessment Field staff need to take a step back Experienced field staff add a great deal to this process Rehabilitation recommendation!
Field Staff Field experience extremely beneficial Opportunity to take program through construction phase very important Lessons Learned are used to modify program & forms
Electronic Data Collection No papers to handle in the field Data can be sorted in a variety of ways useful in developing rehab options Reports easily prepared facilitates project communication Have to be careful!
Rehabilitation Program 2010 1 st Rehab Construction Season 100 manholes rehab d Scope determined by City budget Year 1 Focused on structural issues Year 2 I/I focused 2010 Rehab Techniques Manhole replacement Top replacement Spray-on liner (lower sections of manhole) CIP liner (upper section of manhole) Spray on liner typically used in conjunction with CIP liner
Top Replacement
Spray-On Liner
CIP Liner -Installation Two part resin Resin applied to felt
Distribution of resin CIP Liner Fiberglass mesh reinforcement
CIP Liner Plastic sheeting to isolate liner Inflatable bladder
CIP Liner Examples of finished installation
Questions? Andrew L. Craven, P.E. Strand Associates, Inc Madison, WI Andrew.Craven@Strand.com Is it break time yet?