Board of County Commissioners work session
Water treatment plant filtration upgrade pilot study results
Meeting called to order
Carol Whitmore opens work session
Dan Gray, utilities director
John Zimmerman with utilities department
In 07 we had a work session about water standards. Same plant since 1966.
Same filtration process since 1800s improved on in years.
Can't keep up with new standards.
In 08 approved looking at new techologies.
Finished work.
Mark Simpson
Street Lee
Bill Lott
Mark Simpson to look at results of the study.
Water treatment plan pilot study results.
Recommendation:
Retrofit current sand filters with an ultrafiltration membrane process.
Offers advanced particle removal. Compliance with present and future rules.
Biological Contactor option can be phased in to treat for T&O if current studies confirm earlier results.
Background
Workshops in 07-08
Existing filtration needed rehab.
Water-quality goals - current regulations and future needs.
BCC OK'd.
Ground water and surface water
Two different water qualities and processes.
Ground water from east county wellfield, treat and filtrate, then blend it.
Surface water has high color and alkalinity.
Treated with activated carbon and then coagulation, fluoridation and sedimentation, then filtration. Latter is what we're talking about.
After blending and final treatment, water goes out for distribution.
Why do studies?
Filters are 40 years old. Need to do something.
Need to improve
Evaluate other treatment processes
Minimize water loss
Update treatment process
Review of filters and what they can remove from surface waters.
From left to right, smaller to larger
Conventional filtration is current process.
Takes out large particles, but not a finite barrier and does not touch smaller things like viruses.
Donna Hayes: What is T&O?
Simpson: Taste and odor; total organic carbon.
Second process is low-pressure reverse osmosis.
Greatest capabilities for removing objects. Can take out small stuff like metal ions and viruses. Doesn't work very well on larger particles and fouls the membrance. Need a process in front to take out larger particles.
Next option:
Ultrafiltration. Falls in middle. Takes out algae and bacteria. Complete microbial barrier, and can remove larger particles.
Treatment goals
Turbidity control
Plant meets standards but challenged by algaie blooms.
Taste and odor
Aesthetic concern but it has high visibillity, but is expensive to fix.
Total Organic Carbon reduction.
Plant meets rule comfortably.
TOC are compounds in the water, but disinfecting makes byproducts.
Eliminate byproducts is a goal
Water Loss Minimization
Have to meet goals. It's a limited resource.
Any of those processes have to meet those goals.
Technologies
Ultrafiltration
Low pressure reverse osmosis concentrate stream 15-25% water loss
Ozone with biological active filtration
What do results tell us?
UF is a viable option and meets rules
No treatment alternatives reduce TOC with acceptable water loss
LPRO worked well but with 15-20 % water loss.
Add Ozone, but no significant T&O cuts
O3/BAF - Cut T&O, but no TOC reduction.
Each worked well, but could not meet all treatment goals.
Developed 12 potential alternatives for water quality goals.
2 gone because of hydraulic limitations at plant
Potential alternatives
Granular media filtration
Fixing existing filters - take filters and repair medium. Keeps us going
Bed Depth filter upgrade
Biological contactor and filter repair - pretreatment option
Low pressure RO
10. 54 MGD LPRO - Filter repair, new LPRO, new biological filters, new ozone system
4. Ultrafiltration retrofit - recommended process
5. Ultrafiltration - filter repair, construct new UF syustem and building
7. UF/BAF new system pressure
12. Same as 4, with biological contactor/UF retrofit
8. Ozone BAF - Filter repair, new system
Ability to meet goals
Each alternative rates
Turbidity 60%
T&O removal 20%
TOC 20%
Showing slide with scores.
No alternative reached a perfect 10.
Alternative 12 is at top, 1 and 2 least ability.
Six alternatives meet more than 50% of goals.
Alternative 4 at 6.6 out of 10.
Hayes: Looking at 12 and 4, why recommending 4 and not 12?
Ans. 12 is high, and so is 10. Alternative 12 has biological contactor and is still unproven technology. If it doesn't work at full scale, score could drop.
10 is a low pressure RO system.
You'll see why we chose 4.
COST
12 costs $42.56 million
10 costs $121.75 million
4 costs $35.4 million
4 costs $.195 dollars per
Cost effectiveness of alternatives
Determine additional treatment benefit
Ultrafiltration (4) at 24.6 on scale of additional benefit/cost
10 rates very low
Whitmore: Is ultrafiltration the same as microfiltration?
Simpson: Ultrafiltration is better than microfiltration.
Whitmore: Biological contactor?
Simpson: Basically a big tank filled with carbon. Bacteria in water will hopefully eat bad stuff in water.
Big draws is that it's not a chemical process. "The bugs are chewing it up."
We recommend alternative 4.
Meets current and future regulations.
Provides protection from bacterial risks.
Cuts current chemical cost
Addresses filter rehab needs
Minimal water loss.
Uses current infrastructure.
Biological contactor can be added later.
Ron Getman: Why not 12 over 4?
Simpson: Capital cost on unproven technologies too high. Not confident on recommending it.
Getman: Funding at this point?
Simpson: Management will take it up for consideration for bonding.
Getman: This will take out viruses? Yes. Maybe we can get grant funding through homeland security to protect us from viruses.
Simpson: We can look into that.
Getman: With feds giving money away, this is a good thing.
Simpson: Most of federal money sppoken for.
Getman: Another year is coming up. I'm very pleased with result of studies and opportunity to provide best-quality water in state of Florida. Wonder if bottlers will try to use it.
Congrats on a good test. I support it.
McClash: What different does it make to consumer at the end of the day? Is there a health issue we're doing it for? What are major health issues.
Ans. It will provide an absolute microbial barrier.
McClash: What does that mean to average person? You'll get sick less?
Simpson: Cuts down chance of getting sick. This UF will eliminate challenges.
McClash: Cost to consumer? For less than $1.50 per month, they have health protection?
Simpson: Yes. We're certain of new regulations. We can meet them.
McClash: This has a better chance of eliminating risk of attack?
Simpson: Yes.
McClash: How long does it take?
Simpson: 2? years of construction.
Simpson: We won't be using it on ground water side. Only 2/3 of filters. Of those 2/3, only 1/3 need to be converted to UF.
McClash: We have three setups out there. So we shut down one so we still have two working.
Simpson: This will be phased in. It can be phased in. We won't be taking all offline at once.
Ground water treatment filtration will remain the same.
Whitmore: Safety, security and health. Fear of drugs, bacteria, MRSA. Terrorism worry. "We do need to tell the public that when it leaves the plant it's like that, but then it has to go through 2,000 miles of pipe in county." Breakage there could be a problem. It comes out of water source free of harmful bacteria. Some complain water near islands tastes bad. But you say it's because they don't use too much. Am I wrong or right?
Simpson: Have to start it at the source. There are things that can occur in the distribution system and there are issues, but we're focused on the source.
Whitmore: No guarantee that what's out of the tap is what came out of the plant.
Ans. As Mark said, you start with the source and put the bet product out that you can, and rely on the distribution system to be well maintained. "That's the best that we can do."
We've done a lot of work. We're confident that we can couple that new technology with these upgrades to provide highest quality water. No guarantees, though.
Whitmore: I've been told our water is best.
Ans. Amazing you can spend $1.45 for bottled water, and can spend $1.45 for 1,000 gallons, and quality is essentially the same.
McClash: Good presentation and very clear. Good outcome. Pharmaceuticals are less of a threat. Some have tried to get us to change that policy. I think it's cost-effective. To me, I think the answer sould be yes.
Getman: Went to domestic terror class and had to identify targets. Central water supply was one of the utilities to be targeted. Recommended that max protection be afforded through filtration. We owe it to the community to provide the highest level and quality of service to the community. Now that we know we can do a better job, "We need to do this."
Bustle: Would ASR be treated?
Ans. Yes.
Zimmerman: Option 12 is not off the table. It is something we can phase in. It does improve level of treatment. We expect it to come back to you.
Bustle: Did we do a peer review?
Zimmerman: We looked at others. "Ultrafiltration is really sweeping the country." Ozone and carbon sites are going in. We didn't have it peer-reviewed, but we looked at what was going on.
Hayes: Thanks for good presentation. When you look at 12, you said areas had not been proven. What influenced you about 12? One option was not a great deal more expensive.
Ans. 12 worked on a lab scale in 4-month process. Started processes to see if it works. That phase, then next step. Hopefully, we're close. It's not a new technology, it's just where we're looking at where it's going in the process.
Hayes: Is there a process that state has?
Ans. Only thing I can add is they took what was out there and made sure it could work with our system, and then put it all together to present viable options. I think they have come up with a solid recommendation. Happy and proud of work. John led effort all the way through. The legacy that John will leave is making this utility grow up and leaving us with this next project, which takes us to next level.
Original facility cost $15 million including dam.
McClash: People always ask why you can't do things for less.
Ans. End of presentation. Need to develop funding protocols, then basis of design, full blown design. Full implementation in 2.5 to 3 years.
Brown: Who will look at grant from DHS?
Ans. We'll be looking at it. We're hopeful that this project will quality for the money.
Brown: Let's see what can be done. It may not be today, but in the future, so we end up getting money somewhere down the line.
Whitmore: I know you mentioned stimulus money, but they need to be ready to move. That doesn't apply here. There may be future monies.
Brown: Homeland security has money for water supply every year.
Ans. Homeland security hasn't been looking at treatment side, but are starting to and we're hopeful that they will begin to look there.
Bustle: If a terrorist were to pick Lake Manatee and put something in the water, could this system handle a big spike of some unknown contaminant?
Ans. Depending on what it was, it would take a lot. If it was particulate, this system would catch it. But if it were an organism, not. Our hopes that if biological contactor works, it would be on line all the time.
Hayes: What about detection? Is there a detection device in this system?
Ans. In this system, no. Some would pick it up in testing.
Brown: We look forward to coming back.
Recess
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