Kevin Colvett, P.E. Nashville Corrective Action Plan and Engineering Report, Phase III for Metro Water Services and the City of Brentwood, TN Presentation to TDEC – August 28, 2014

Agenda 1.Prior to 2008 a)Brief Review of System Hydraulics b)Regulatory Order c)Process for Writing the Original CAP/ER 2.CAP/ER – Implementation years 2008– Current analysis 5.Completion strategy

Prior to reported overflows at the Brentwood Pump Station in 2007 – the drought of record year Average flow was near 6 million gallons per day (mgd) No agreement on a viable solution Result was regulatory order – Case #

Order Required a Corrective Action Plan to be jointly submitted by Metro and by Brentwood CDM was hired to perform the work Utilized MWS long-term flow data and GIS as well as best information available from Brentwood – some of which was temporary flow monitoring data from drought year of 2007 CAP/ER submitted in 2007 and approved in February 2008, but “path forward” was clear earlier than that

Results of the Original CAP/ER 2014 – ON SCHEDULE

2008–2013 Metro issued Consent Decree Economic slowdown impacts revenues and growth 2010 flood impacts projects Frequent updates provided to the Division 1-year extension granted

Work Performed Since 2007 Rehab of close to 20% of the Little Harpeth River system (more than anticipated) Reduction of over 1 mgd of flow from the system Reduction of overflows in the system by ±90% Savings of over $1 million per year in master metered flows to Metro Brentwood awarded “Rehab Program of the Year” at 2014 WPC in Chattanooga

Work Performed Since 2007, cont. Moratorium relaxation/essential lifting Zero regulatory actions Removal from CMOM watch list – “matter closed” through 308 letter response Spent $24 million on sewer rehabilitation

Flows at the Brentwood Pump Station 2008–2013 Note Very Few “Spikes” Approaching 9.5 mgd Capacity

Overflows in Brentwood’s System 2008–2013

Modeling of Current Conditions Approach was to emulate the modeling work done for original CAP/ER and update with current flows and GIS information Utilizing this information, the calibrated model can be run for various scenarios, centering on: –Additional Rehab –Storage –Additional Pump Capacity

The system is showing a lower response to rainfall after the rehab work but the system response continues (Regression Limb Comparison)

Current 2-yr 24-hr Storm

Equalization Only Option Model output: EQ basin at BPS would need to be 3.0 million gallons (MG)

Additional Conveyance Model output: need to pump 3.5 MG more to accommodate 2-yr storm –Not recommended because of difficulties in routing the new force main and other downstream improvements; existing 18” force main at capacity

Possible Flow Reductions by Continued Rehabilitation 25% Additional R Value Reduction

MWS and Brentwood Brentwood to continue rehabilitation in the Little Harpeth River Basin through 2019 –Continue to update TDEC on rehabilitation plans and efforts –Focus more on service connections –Approximate total cost $1M–$2M per year –Continue long-term flow monitoring –After 2019, commit to “annual rehabilitation” through CMOM / asset management programs MWS to continue rehabilitation in the basins contributory to the Pump Station –Propose investigative work in RI08, RI09 and RI10 in 2015 –Propose design in 2016 –Propose construction in 2016/7 –Approximate total cost $1M –Continue long-term flow monitoring –After 2019, continue CMOM efforts in these basins as required by the EPA / TDEC Consent Decree for the rest of the MWS system.

Information Requested From TDEC 1.What sort of concurrence will TDEC provide for both the report and for the work stemming from it? In essence, how will it be noted that Order compliance has been attained? 2.Is a plan that outlines specific corrective action but does not guarantee a particular flow reduction acceptable? 3.Is a time extension past 2016 justified given recent progress, the time required to design and procure improvements, and the time required to quantify improvements? 4.Logistics for submitting the final report by the end of September.