Clean Water Project

 Completion of the south conveyance tunnel (SCT) is important to meet the requirements of a CT DEP Combined Sewer Overflow (CSO) consent order and Storm Sewer Overflow (SSO) consent decree. It will be designed and constructed over an estimated three years.  CSOs from the southwestern part of Hartford will be captured and directed to the SCT, and later SSOs from West Hartford and Newington will be captured and routed to the SCT. This work will relieve the South Branch of the Park River drainage area and reduce the storage otherwise required of the new deep rock tunnel.

 Risk (1) – Discovery of Large Caverns limits site possibilities  Consequence of occurrence - 4  Re-site tunnel  Increased Overall Cost  Increased Time  Likelihood of occurrence – 1  Unlikely to find Limestone under Hartford: Caverns require Limestone  Cost/Time Reserve  20% cost Reserve  40% time Reserve

 Risk (2) – Access to Land for Testing  Consequence of occurrence  Delays in Siting Decisions - 3  Increased Overall Cost  Increased Time  Likelihood of occurrence – 4  Large number of property owners  Weather Uncertainty  Cost/Time Reserve  5% cost Reserve  10% time Reserve

 Risk (3) – Delays due to Addendums ◦ Consequence of occurrence - 2  Delays Award Date and therefore construction ◦ Likelihood of occurrence - 5  Common Occurrence  Cost / Time Reserve  30% cost Reserve  10% time Reserve

 Risk (4) – Lawsuits Challenging Contractor Selection ◦ Consequence of occurrence - 5  Delays Award Date and therefore construction ◦ Likelihood of occurrence – 1  Cost / Time Reserve  20% cost Reserve  20% time Reserve

 Risk (5) – Unknown Conditions (“Unknown Unknowns”)  Consequence of occurrence - 2 ◦ Plan Redesign / Change Orders ◦ Higher Cost ◦ Longer Duration  Likelihood of occurrence – 5  Cost / Time Reserve  25% cost Reserve  25% time Reserve

 Risk (6) – Large Tunneling Equipment Failure  Consequence of occurrence - 4 ◦ Delays ◦ Higher Cost  Likelihood of occurrence - 1  Cost / Time Reserve  10% cost Reserve  50% time Reserve

 Subject to penalties by DEEP  Higher Risks associated with Overflows  Increased Pollution of public waterways  Backed up Houses

 Budget Overruns resulting from delays  Increased cost associated with Unknowns  Penalties for late completion

ScoreConsequenceDefinition 5Very HighProject Failure 4HighSignificant (75%) degradation in project benefits 3ModerateModerate (50%) degradation in project benefits 2LowSmall (25%) degradation in project benefits 1Very LowMinimal (or no) degradation in project benefits ScoreLikelihoodDefinition 5Very HighAlmost certain (>70%) 4HighMore likely than not (>50%) 3ModerateSignificant (>30%) 2LowUnlikely (>5%) 1Very LowVery unlikely (<5%)

 Lots of Test Pits  Public Information Campaign  Attorney Review  Objective Bid Scorecards  Cost and Time Reserves  Bonding of Contractors