Water Treatment Plant No. 2 Concentrate Zero Liquid Discharge

Water Treatment Plant No. 2Concentrate Zero Liquid Discharge

Water Treatment Plant No. 2

• Membrane Softening Water Treatment Plant completed in 1992.– Upper Floridan groundwater wells provide the

source water for treatment.– Treatment process produces concentrate or

“byproduct” stream.– Concentrate is currently discharged into the

Royal Palms Waterway.

Map of WTP 2 and Discharge Point

Water Treatment Plant No. 2Permitting

• The current permitted production is slightly more than 6.3 Million Gallons per Day (MGD.)

• The amount of source water required to obtain 6.3 MGD of finished water is 7.5 MGD.

Concentrate

Permeate

Groundwater

Byproduct water~1.2 MGD

Drinking water ~6.3 MGD

How did we get here?• EPA determined the current concentrate

discharge method is not allowed by the Clean Water Act.

• FDEP notified the City via an Administrative Order on May 1, 2008 that the concentrate disposal permit would NOT be renewed.

• The Administrative Order requires the City to devise an alternate method of disposing of the concentrate.

How did we get here?• An evaluation of concentrate disposal

alternatives based on costs and regulatory compliance was completed 2009.

• Selected Zero Liquid Discharge (ZLD) for a Pilot Study based on evaluation results.

• ZLD Pilot Study confirmed the treatability, feasibility, and economics as favorable in 2010.

• Selected McKim and Creed Engineers to design and permit the ZLD process in October of 2011.

What is Zero Liquid Discharge (ZLD)? • A lime softening/filtration process that treats the

concentrate stream to remove excess mineral content.

• The ZLD treated finished water is blended with finished water from the water plant.

• Excess minerals are removed by the process and are contained in the dewatered lime sludge (similar to WTP#1) and hauled off-site.

• The new ZLD Process will be integrated into the existing water treatment plant and will operate as one facility.

Action List

• The City advertised the ZLD project for bid in May 2012 and received 6 bids.

• Wharton-Smith Construction (builder of WTP#3) was the lowest bidder with a price of $9,542,000.00.

• Wharton-Smith Construction will hold their price even though the bid opening was held over ten months ago in June 2012.

Project Benefits• Achieves regulatory compliance.• Increases water plant design capacity by ~1.2

MGD(equal to 3 wells).• Eliminates discharge permit and associated

sampling costs.• Meets the Consumptive Use Permit requirement for

Alternative Water Supply.• Incorporates City’s green initiatives by conserving

water, recovering and using a byproduct water while providing an environmentally sustainable solution.

• Delays costs associated with future expansions.

• Propose to split the contract into two phases to allow for pre-construction activities to begin while sale of the 2013 bond issuance is completed.

• Phase 1: Pre-Construction Services Only.Cost: $100,000.00

• Phase 2: Construction Services.Cost: $9,442,000.00

• Adopt “Resolution to Award”• Adopt “Resolution for Bond Fund Reimbursement”

(legal requirement to use 2013 bond revenue)

What do we do now?

Project Schedule

• Award construction contract/phased plan: May 2013 phase 1, July 2013 phase 2

• Competitive sale and award of bonds takes place - June 11, 2013

• Bond Closing completed - July 9, 2013• Estimated Substantial Completion and

Administrative Order compliance: September 2014