Weymouth Plant. Diemer Plant. Mills Plant. Skinner Plant

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1 Weymouth Water Treatment Plant Weymouth Oxidation Retrofit Program

2 Appropriate $9.8 M in budgeted funds Authorize final design to complete Weymouth Oxidation Retrofit Program Authorize final design of Weymouth raw water bypass line Authorize amendments to exist. agreements with Carollo Engineers & Tetra Design

3 Jensen Plant Weymouth Plant Diemer Plant Mills Plant Skinner Plant

4 Weymouth ORP and Raw Water Bypass

5 Effective, reliable disinfection Minimizes DBP formation Controls Taste & Odor Removes disease causing organisms Removes many PPCPs and EDCs Flexibility to manage shifts in source water quality Permanent strategy at all 5 treatment plants

6 Minimize disinfection by products by Increasing coagulant & acid dosages Delaying point of chlorination Temporarily reducing SPW blends Ensures Weymouth will continue to meet all primary drinking water regulations with operational constraints Disadvantages Limited control of Taste & Odor Source water limitations Higher TDS Potential limitations on plant capacity

7 April 2007 Bid Package Ozone facilities Inlet conduit Some electrical upgrades Access constraints Weymouth full plant shutdown revealed need for new rehabilitation projects Phased approach implemented Lower risk of construction delays Lower risk to plant operations

8 Weymouth 3 Phased Construction Approach Phase 1 Electrical Projects, Plant Inlet Conduit, Infrastructure Upgrades Phase 2 Ozone Implementation Phase 3 Process Improvements

9 Final Design Tasks Develop bidding documents for phased approach Structural design update to comply with new building codes Rejection line to Marshall Creek Channel District Force work Control systems & chlorine system modification Design Joint effort Metropolitan staff, Carollo Engineers & Tetra Design Amend agreements with Carollo Engineers & Tetra Design

10 Labor Owner Costs (Program mgmt, $805,000 permitting & biddingprocess) Final Design $6,665,000 Incidental le Expenses $25,000 Professional/ Technical Services Carollo Engineers $680,000 Tetra Design $125,000 Environmental Science Associates $45,000 Remaining Budget $1, Total $9,560,000

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12 Design scope of work Connection to Upper Feeder Vault for temporary pipe spool upstream of ozone contactors Modifications to vault near finished water reservoir for another temporary pipe spool Bypass will be constructed during the ORP Carollo Engineers will perform final design under an existing agreement

13 Labor Owner Costs (Program mgmt & $48,000 permitting) Incidental Expenses $2,000 Professional/ Technical Services Carollo Engineers $158,000 Remaining Budget $32,000 Total $240,000

14 Weymouth ORP Schedule Project ORP Raw Water Bypass Final Design Shutdown Window/ Shutdown Advertise/Award Board Action Construction Completion of Construction

15 Option # 1 Adopt CEQA determination Appropriate $9.8 million Authorize completion of final design of Weymouth ORP Authorize final design of a raw water bypass line for the Weymouth plant Authorize an increase of $1 milion to existing agreement with Carollo Engineers, for new NTE total of $12.7 M Authorize an increase of $200,000 to existing agreement with Tetra Design, for new NTE total of $2.658 M

16 Option # 2 Adopt CEQA determination Appropriate $9.56 million Authorize completion of final design of Weymouth ORP Do not authorize final design of a raw water bypass line for theweymouth plant Authorize an increase of $1 milion to existing agreement with Carollo Engineers, for new NTE total of $12.7 M Authorize an increase of $200,000 to existing agreement with Tetra Design, for new NTE total of $2.658 M

17 Option # 3 Do not proceed with ozone facilities at Weymouth at this time

18 Option #1