Presentation on theme: "Brushy Creek Municipal Utility District Water Facility Project Status Update Presented at April 9, 2009 Board Meeting Joseph Jenkins, P.E., CH2M HILL."— Presentation transcript:
Brushy Creek Municipal Utility District Water Facility Project Status Update Presented at April 9, 2009 Board Meeting Joseph Jenkins, P.E., CH2M HILL
Engineering Projects Intake Repairs – goal to make sure the operation of the intake remains reliable and safe until more permanent upgrades can be completed. Coordination with Chisholm SUD and City of Georgetown on use of some of Brushy Creek MUD’s intake structure and electrical building site for their new intake and water plant facilities – goal to be cooperative without compromising desired current and future levels of operability and make sure upgrades are compatible with these future plans, i.e., location of surge tank and electrical building. Membrane Testing – goals – to meet TCEQ requirements, increase capacity, protect membrane investment to water quality changes.
Intake Repairs Testing of medium voltage cables and transformer at intake complete – acceptable for continued use. Pumps No.1 and No.3 are now in good reliable operating condition. Working with Plant staff to modify automated pump valve controllers. Signal and electrical shorts from flood have damaged relays and electronic controller. New splice to repair damaged cable on Pump No. 2 has been made but is not sealed yet. Power to compressor building – new breaker to be installed to determine if we can get power to intake structure – if not, temporary power from compressor building can be “run-down” to intake. CH2M HILL will provide report on testing and any final recommendations for repairs before more permanent upgrades will be made.
Pump No 2. Cable Repair step
Proposed Shared Intake
Intake Next Steps Brushy Creek MUD should make any remaining recommended repairs to intake for safe reliable service until upgrades constructed. CH2M HILL to provide proposal to begin design of permanent upgrades. Finalize agreements with Chisholm and Georgetown – design and construction to have some shared cost
Membrane Testing History of the Brushy Creek Water Facility July 2001 – Naismith Engineering/CH2M HILL completed PER –established treatment and capacity April 2002 to July Membrane Pilot Testing – established flow per membrane area on Lake Georgetown Water July 2004 – Design complete – TCEQ approves provided we check membrane operations with Stillhouse and Georgetown waters 2006 Plant starts operations and Stillhouse water beginning to be pumped to Lake Georgetown 2009 – Higher capacity needs, different water quality and need to test for TCEQ
Plant must have capacity for a peak day water demand. During design 6.25 mgd capacity selected – uncertainty of growth projections and relative ease of expansion. Demands are now at plant capacity – need additional capacity accepted by TCEQ Key is to balance capacity against membrane cleaning. The fewer membrane cleaning cycles the longer the membranes last. Things that effect membrane fouling – flow and water quality Plant Capacity
Changes in Water Quality Record Flood – short term suspended solids, manganese, low pH, low alkalinity – increase in fouling Record Drought – warmer water, higher organic foulants – algae – increase in fouling
Raw Water Turbidity Average up to 2001 – 3.5 NTU/ NTU
Raw Water Manganese
Raw Water Hardness
Status of Membrane Testing Effort- Completed Task 1, Initial Evaluation of Task 2, Draft of Task 3 1.CH2M HILL to identify TCEQ requirements. Summarize in TM. 2.CH2M HILL and BCMUD staff to define testing goals, including flux rate or flow rate to be the target for the test. Confirm with Pall the wash cycles and mode of operations. CH2M HILL to summarize in TM. 3.CH2M HILL to develop a detailed protocol for 30-day test. Submit to TCEQ for approval. Make changes as required by TCEQ. 4.BCMUD staff to operate selected test rack for 30-day test following approved protocol. CH2M HILL to provide limited technical support. 5.CH2M HILL to prepare report outlining full-scale test results. Submit to BCMUD and TCEQ for review/approval.
Initial Findings Staff has made some positive changes to adjust to changes – change to a coagulant that has recently shown to be more effective for membrane systems, added more modules Some foulants still continuing to require membrane cleaning at higher rates than desired for capacity and membrane life. With the addition of the modules and by addressing the foulants, there is a significant opportunity for higher capacity and less cleaning – thus meeting some important goals – more capacity, better adjustment to changing water quality, few cleans – which protects your investment and extends its life.
Recommendation To get the best value of the plant, get the best rating we can from TCEQ by making some upgrades for capacity and treatability
Upgrades UpgradeUseBenefitCost Range (capital) Additional water softener Soft water must be used for cleaning membranes otherwise scale can form Higher wash volumes for more capacity and complete cleans quicker. $40,000 to $45,000 Additional air scrub capacity Air is used to scrub and clean membranes along with chemicals – more modules need more air Better cleaning and protection of membranes $75,000 to $85,000 Addition of sodium permanganate to raw water Oxidizes manganese and organic compounds Reduces manganese levels to the membranes $60,000 to $80,000 Increase storage of cleaning chemicals and blend tank Chemicals used to clean membranes More modules require higher wash volumes – need more storage that is also makes it safer for handling $60,000 to $80,000 Backwash supply TankWater used to flush membranes after cleaning Better cleaning and protection of membranes $20,000
Upgrades UpgradeUseBenefitCost Range (capital) Spare Rack Mounted air Solenoids - Controls valve air on racks 6 weeks to order – rack would be down if not working $10,000 Improve Decant basin solids settling Basins settle solids and recycle water back to ponds Reduce organic loading to ponds – lower disinfection byproducts $20,000 to $30,000 MiscellaneousOther ancillary needs like air filters on racks, lab instruments Improved operations$15,000 to $25,000 Total$300,000 to $375,000 Does not include engineering cost
Next Steps Make Upgrades Submit test plan based on upgrades Test Potential to get 2 mgd more capacity with upgrades than if not done – that $0.19 per gallon of treatment capacity – compared to new plant that is $3 per gallon of treatment capacity.