2026-09-23 - Water Pollution Control Authority Special Meeting

00:25Okay, I'd like to call this um special

00:28meeting of the Killingly Water Pollution

00:30Control Authority

00:32uh on September 23rd

00:35to order. It's uh 502.

00:38And um as far as our members here, we've

00:43got uh all of our members except for

00:45Brian.

00:47He um called me and told me he's running

00:49a few minutes late, but he uh he should

00:52be here shortly.

00:55So item two is citizen participation.

00:58Any citizens uh wishing to um speak or

01:03would be welcome to do so now.

01:07Mr. Grandski.

01:09>> Yeah, I think this is a a you know,

01:11bringing this presentation forward. It's

01:13a it's a it's a good opportunity to see

01:15what's going on and uh I hope we're

01:18going to make some headway. Um at the

01:21last meeting, we had, you know, a number

01:22of individuals that were looking and

01:24saying the economics uh economic

01:26development is kind of at a standstill

01:28because we we got to get this project

01:31moving on. So

01:34this is the right direction. Thank you.

01:38>> Okay, Mr.

01:38>> Thurlo,

01:41>> where does turn this on and is it on

01:43automatically?

01:46>> Can you hear me?

01:51>> So, I just want to acknowledge that it's

01:54nice to see everybody here at the town

01:55hall. I know you're not exactly fans of

01:58it, but it lets everybody see what's

02:00going on. lets the town know what you're

02:03doing and uh what we're all about. I

02:06mean, you do got a $6 million budget and

02:08I mean, let's face it, at the last

02:09meeting, you guys spoke about having u

02:13uh transparency

02:15and this would add to your transparency.

02:18You were concerned with transparency

02:19when it came to legal legal uh on legal

02:23line items on your budget

02:26and uh this adds to the whole whole

02:29thing. So, uh, I'm just glad to see it

02:32and hope it stays this way. I know you

02:34don't want it that way, but I think it

02:36should.

02:39>> Thank you. Please, yeah, just state your

02:42name as you come up.

02:43>> Uh, Bill Chance. I'm uh, you know, 25

02:46Huntingber way. Um, David, I'm killing

02:49the EDC chairman. Um uh I stand you know

02:52say I attended you know the couple you

02:54know WPCA you know the meeting talk

02:56about it you know so small business in

02:59town is say the um change of use. So um

03:04WPCA is pretty much a limited you know

03:07say opportunity to grow in downtown or

03:10in killing me any small business that

03:13come in wherever that person use the

03:15building you pretty much you can change.

03:19So um I have a couple question to ask.

03:22So what is the outcome and how long are

03:24the way and um next you know say um you

03:29know the project expansion

03:32when you look into that and say the 10

03:34year 20 year I live in town 42 year I

03:37don't see much change but definitely is

03:40a change a lot since the 1984 come to

03:43today you see the traffic you see the

03:45people moving in from uh triate area you

03:49know from New York I'm also another head

03:51is I'm a realtor. So we see the people

03:54coming in. Yes. So we got to change up

03:57with the time and see how we can do

03:59better for the future.

04:02I don't know as a um uh the warehouse

04:05project will have a sure line is a make

04:08a change. So that is a key word is a

04:11look forward for how long maybe you you

04:14got to you know the five year or 10 year

04:16you all fill it up. So the decide what

04:18is a you know got to be up to the you

04:20know the up to the day you know say what

04:22we need. Thank you.

04:30Anyone else want to care to speak?

04:34So we're going to hear more about the

04:35facilities plan. That's what the uh

04:37primary focus of this meeting is on

04:40tonight. Our consultants are going to

04:41give a presentation and uh it's based on

04:45a 20-year plan.

04:48Okay.

04:50All right. Are the um is right Pierce?

04:58>> Good afternoon. Can you hear me?

05:00>> Yeah. Hi Dylan.

05:03>> Hey. Yep. [clears throat]

05:06So, we're just we're um if you could go

05:08through the you know the workshop plan

05:10that you like you presented it uh back

05:14um two weeks ago that would be great.

05:21>> We can get your slides up too.

05:24>> Yeah, for for sure. For those of you who

05:26I haven't met in person, um my name is

05:28Dylan Atkins. I'm the one uh primarily

05:32working on the evaluations for the

05:34Killingly water pollution control uh

05:37facility.

05:39Um I've been in the wastewater industry

05:43for over 15 years. I started pumping

05:46septic tanks for my father and uh now I

05:50currently work in the wastewater

05:53executive committee for Wright Pierce

05:56which means I am primarily uh working in

06:00on the biological treatment systems uh

06:03not necessarily designated to an

06:04individual state or area. So with that,

06:08I'm going to share my screen and get

06:10into the presentation I uh gave in

06:13person previously.

06:29>> Can you all see the presentation?

06:34>> Yes.

06:39All right, great.

07:05Okay. So the agenda for this

07:07presentation

07:09uh is going to go over the facility

07:11flows and loads

07:13the effluent treatment go the effluent

07:16goals that impact the the treatment

07:18analysis and the decisions we're making.

07:21uh I looked at uh some interim capacity

07:25increase and then some mainstream uh

07:28capital improvement cap capacity

07:30increases.

07:32I got about 40 slides. I'm going to try

07:34to go through them fairly quickly and

07:38I'm aiming for about an hour to an hour

07:40and a half presentation with questions

07:43uh afterwards.

07:48And so uh we're going to start with the

07:50the flows and loads.

07:53We did draft a detailed technical

07:55memorandum

07:57and

07:58distributed uh to the

08:03water pollution control authority.

08:05And uh that goes into much more detail

08:09than what I'm about to cover in the

08:10slides. I'm just going to hit on the

08:12major topics and uh from that memo that

08:14impact the analysis that I've done.

08:18So the facility

08:20ranges from about 1 mgd to 7 mgd on a

08:25daily flow uh total gallons treated. Um

08:30the average is around 3.4 4 MGD

08:34and uh maximum month flows or maximum

08:3830-day rolling averages are around uh 5

08:41and a half MGD.

08:44The loads, that's really what we care

08:46about treating. Uh

08:48we have the uh biochemical oxygen demand

08:51and the total suspended solids that we

08:53have to treat. Uh this figure shows a

08:56the trend of 30-day average BOD and TSS

09:01loadings. The uh the key here is that

09:05the maximum 30-day average or the

09:07maximum month that we have to treat

09:09right now is around uh 16,000 lbs per

09:12day. It occurs when the wastewater is

09:15relatively cold and uh around 14C. So

09:20those are the conditions that we're

09:22really looking uh that that really

09:24control the biological process.

09:30Um

09:31I just wanted to highlight that this is

09:33a facility that gets impacted by uh a

09:38known industry. the the industry uh

09:41Fredo Lelay contributes about twothirds

09:43of the uh average load to the facility.

09:50When when we design uh and perform these

09:55uh facility plan evaluations,

09:57we're not necessarily uh concerned about

10:00just what is the existing load. We need

10:01to factor in what the future growth is

10:03going to be. And so at this particular

10:06facility, we have a an allocated growth

10:09for residential load, commercial,

10:11industrial, uh the town of Brooklyn, and

10:14then uh some extra reserve capacity for

10:16freed. So that gets us into the going

10:19from our current average load of 9,400

10:22lb per day to around 15,000 lbs per day.

10:29As I said before, the maximum month

10:32condition is really what we need to

10:33treat because we have 30-day limitations

10:36on our effluent quality.

10:38So, I'm not really necessarily concerned

10:41about that 14,800 lb per day on average

10:44so much as that future maximum month

10:46condition where we estimate we can be up

10:48to around 22,800 lbs per day.

10:56>> [clears throat]

10:57>> These figures

11:00are in here to kind of highlight the uh

11:02to give some perspective of what is

11:05happening

11:08outside of freed.

11:11So if we take free delay out of the

11:13equation, the projected

11:172,800 lb per day growth is about 40% of

11:20what we estimate the existing

11:22residential, commercial, and industrial

11:24users are.

11:27When you factor in the future 9,800 lb

11:29per day design for

11:34uh the users outside of Freedolay, that

11:362,800 lb per day is about onethird of

11:39that that load.

11:45Okay. So that's all on the influence

11:47side of things. I can't change that. Uh

11:50what I can do though is affect uh what

11:52leaves the plant. So

11:55uh what really drives the processes I

11:58evaluate and uh the calculations I do is

12:01about what I need coming out of the

12:03plant.

12:06And at this facility, nutrients are

12:11uh of concern. The first one that we do

12:14have a hard limit on is the total

12:17phosphorus limit.

12:20This is an 18 pound per day limit that

12:23can leave the facility no matter what

12:25the flows are. At the design average

12:28flow,

12:30that 18 pounds per day backs into about

12:3204 millgrams per liter.

12:38So a a big question that we have to

12:40answer is can I get down to 0.4 milligs

12:44per liter using the existing method of

12:49adding a chemical to precipitate

12:51phosphorus out and let it settle in

12:54settle by gravity or can I do I need

12:58some other method to take the phosphorus

13:01out other than gravity i.e. like a

13:03filter.

13:05Uh so to answer that question

13:08I I evaluated what we are currently

13:11doing at the facility.

13:17The facility

13:20gets down to about 0.4 which is our

13:23target.

13:25The

13:29the only issue with this is that there's

13:33no safety factor. And and to be able to

13:35say 100% we are going to be below 18

13:38pounds per day, well, we really have to

13:40be below that 0.4 milligs per liter.

13:45And

13:47so

13:49at some point,

13:51uh, tertiary filtration is going to be

13:53required.

13:58to kind of uh

14:02display

14:04the

14:06relationship between the flow of the

14:08facility and the effluent phosphorus and

14:11how that impacts the mass that leaves

14:13the facility. I put this figure

14:16together. So on the x-axis what we're

14:17looking at is the

14:21effluent phosphorus

14:23leaving the facility

14:26and

14:31given that effluent concentration and a

14:33given flow rate i.e 3.4 4 4.5 5.5 mgd we

14:39can calculate what the mass is leaving

14:42the plant and so that's what each of the

14:46curves

14:47or the lines represent

14:50associated with each flow rate and

14:55let me see if I can get my pointer going

14:57here

15:00okay so

15:03if I have 0.5

15:05milligrams per liter leaving the plant

15:08and I have a 3.4 mgd flow rate, the mass

15:13of phosphorus leaving the facility is

15:15going to be around 13 pounds per day. So

15:18that's how you read this figure.

15:21And

15:22if you go down to the 0.4 that we're

15:25currently getting at the 5 1/2 mgd, we

15:28are going to be at the 18 pound per day

15:30limit. Therefore,

15:33if we're at 5 1.5 MGD, we really need to

15:36be less than 0.4 to have any sort of

15:40safety factor below our limit.

15:45If you interpolate the existing flows to

15:49the projected flows over 20 years

15:52and you want to upgrade the facility

15:54before you get to the 80% limit, 80% of

15:58your limit, you're looking at a tertiary

16:02phosphorus

16:03uh system needing to be implemented in

16:06about 10 years.

16:12Now

16:14nitrogen is different than the

16:17phosphorus in the sense that it's a

16:20uh it's not a hard limit. It's a waste

16:22load allocation.

16:24So if we have a total nitrogen mass

16:30at the end of the year that's above our

16:34allocation, we have to pay credits to

16:38balance the nitrogen load out. And if

16:41we're below the mass limit, then uh we

16:45can sell our credits.

16:48To put things in perspective,

16:51the the facility currently averages just

16:53slightly above the waste load allocation

16:56and is uh buying credits

17:00um between $2 and $3,000 a year uh on an

17:05estimate.

17:13So

17:14similar to the phosphorus evaluation, I

17:18I looked at the existing total nitrogen

17:21removal performance of the facility to

17:23identify what is a total nitrogen

17:26concentration

17:29that I can guarantee to be under to

17:31evaluate what uh cost of future credits

17:33may be if we either keep the existing

17:37process or upgrade to a more uh

17:41efficient total nitrogen removal

17:44technology or process.

17:46Um,

17:48for those of you that

17:51are not familiar with the

17:55process at the treatment facility, I'll

17:57I'll get to that in a minute. It's it's

17:59called the MLE process or modified blood

18:02edinger process.

18:07Um,

18:08I wanted to look at the cost of credits

18:10to identify whether it would be

18:12beneficial to

18:15upgrade to a more uh efficient nitrogen

18:17removal process. Uh, and the the key

18:22takeaway that I found is that the over

18:23the last 10 years, the nitrogen credits

18:25haven't really fluctuated

18:27uh or inflated in a significant manner.

18:31They're they're fairly stable around

18:32$5.60

18:34uh per credit.

18:38So when I look at the the cost of buying

18:40credits or selling credits depending on

18:43the the process I have I looked at the

18:45bard info process or the MLE/ A2O

18:48process. The MLE/ A2O is going to

18:52perform similar in total nitrogen. The

18:54MLE and the A2O are slightly different

18:56in that the A2O will have more

18:58biological phosphorus removal. The bardo

19:01process uh

19:04has extra zones on the back end of it

19:09that further remove nitrogen.

19:12And over

19:14uh 20 years I can look at what is that

19:17cost balance of implementing a a more

19:20advanced process or keeping the existing

19:22MLE. And so what I did is I I looked at

19:25each year and I said if I have the MLE

19:29uh process or the B info process, what

19:32is that nitrogen balance at the end of

19:34the year? And what each of these blocks

19:36represents is the the amount

19:40uh

19:42paid or

19:45uh returned from buying or selling

19:50credits.

19:53So

19:55annually with the MLE process, you're

19:57you're looking at buying credits

20:01between 10 and $40,000 a year depending

20:04on the the future flow rate and how much

20:07mass you're over your allocation. And

20:10then uh if you're selling credits with

20:14the B info process, what you end up

20:18is and is at it about selling them for

20:20about a,000 to $7,000 a year. And so I

20:23can add up the the total amount gained

20:27from implementing the B info process and

20:29I can add up the total amount uh spent

20:33by buying credits with the MLE process

20:36and I can look at the total delta. The

20:37total delta is around $620,000

20:41over 20 years.

20:44And the the key takeaway is that we

20:47can't implement a B info process and put

20:50in the infrastructure the equipment

20:54required

20:55for anywhere close to $620,000.

21:00And so our recommendation is to move

21:01forward with the MLE process that you

21:04currently have. and um

21:09uh leave space in the future for the

21:11ability to add on the extra B info zones

21:15should the allocation become a hard

21:18limit.

21:23So real quick on that uh recommended MLE

21:26A2O process I I do recommend putting in

21:29the the upfront anorobic zone of the A2O

21:33process. So the existing facility has an

21:36existing anoxic zone followed by an

21:39airrated zone and then secondary

21:42clarifiers. The the airrated zone gets

21:46recycled into the anoxic zone to promote

21:49denitrification.

21:51And this anorobic zone is recommended to

21:54be uh implemented to promote biological

21:59phosphorus removal and and potentially

22:01get that 0.4 four that we're getting out

22:03of the facility down just a little bit

22:05lower. And so that we can as we uh as we

22:10move forward over the next 10 years and

22:12start approaching that

22:15um phosphorus limit, we might be able to

22:17push that upgrade off uh if we can start

22:20getting better performance out of the

22:22biological phosphorus removal.

22:28Okay.

22:30So

22:33going through the influent flows and

22:34loads, the effluent requirements and how

22:37that impacts what specific process we

22:41are designing around or evaluating the

22:43facility around. And um

22:48that's that's all good and all, but the

22:51the facility is out of capacity now,

22:53right? And so we wanted to look at

22:55potential

22:56ways to increase the capacity.

22:59And

23:01the two

23:07places in the facility to potentially

23:10increase the capacity revolve around the

23:12uh or what really limit the capacity

23:14currently are the primary clarifiers and

23:17the secondary clarifiers.

23:21Uh the primary clarifier is currently

23:26remove solids

23:30less than what the industry standard is

23:33and that impacts the organics that are

23:35removed in the clarifi in the primaries

23:37as well. Um

23:40the secondary clarifiers at the facility

23:42are susceptible to occasional wash out

23:45due to high flows. And so I wanted to

23:47look into those two places. uh

23:50specifically.

23:55So what I did is I plotted out the

23:57primary clarifier performance the uh the

24:01TSS removal and the BOD removal uh is

24:07uh in the orange and blue line

24:09respectively.

24:13The key here is that orange line is is

24:16hovering right around that 40% for most

24:19of the uh time frame evaluated.

24:23Um

24:24the BOD

24:26is actually right around 0% removal and

24:30uh oftent times actually adds load to

24:33the secondary process.

24:36And so

24:40the

24:42there's a few things that can impact

24:43that and that's recycle loads from the

24:46solids handling process

24:49and uh potential fermentation of sludge

24:51within the primary clarifiers

24:53themselves.

24:55Um,

24:58if I want to increase the performance of

25:00these clarifiers, there's the potential

25:02that I could add some uh metal salt to

25:04it to to help precipitate out um solids.

25:10Uh that does add more chemical to the

25:14existing process and the facility and

25:17we're going to try to stay away from

25:18that uh initially. Um

25:22the the other thing that I can do is

25:25kind of look and see like hey is there a

25:27potential fermentation

25:29developing within the the the clarifiers

25:32themselves from the the sludge sitting

25:34in there. And so what I wanted to do was

25:38I wanted to look at uh the capacity of

25:41the primary clarifiers

25:43and uh whether we have the ability to

25:46decrease the amount of sludge sitting in

25:48the clarifiers all the time and uh thus

25:52reduce the potential of fermentation.

25:55And so working with operators, we've

25:58decided to take uh one primary clarifier

26:01offline initially and start sampling

26:06uh before and after the clarifier to

26:08evaluate uh how the process

26:13modifications

26:15uh affect the performance of the

26:17clarifiers. And and the the big picture

26:20here that we need to uh focus on is if I

26:23can take out

26:26you know, a thousand more pounds of BOD

26:28in the primary clarifiers.

26:30Well, then I can accept a thousand more

26:32pounds of BOD on the influent. Um the

26:38the the thing to remember here though is

26:43we have to see a sustained improved

26:45performance

26:47before

26:49we can make any adjustments of uh

26:53influent loadings that we can accept. So

26:57while this is an interim capacity

26:59increase analysis, there's no guarantee

27:01that taking a unit offline

27:05is going to

27:07uh

27:09result in a BOD

27:11uh load decrease to the secondary

27:14process.

27:16It's just the only things that we have

27:19at our uh you know abil you know that we

27:21have ability to control that that may

27:23help us. So, we're working with

27:26operators now and uh we're kind of going

27:29down this investigative road to to see

27:31if we can squeeze a little bit more

27:33capacity out of the existing facility.

27:37Um

27:38the secondary clarifiers was the the

27:41next spot that I wanted to look at. And

27:45for these clarifiers in particular, when

27:48you're designing them, you need to have

27:50so much of clear water on top of the

27:52sludge blanket in the clarifier.

27:55The amount of clear water required can

27:57be calculated for any given flow rate.

28:00And so if I what I've plotted here

28:04is

28:06for any given flow rate, how much clear

28:09water do I need on top of my sledge

28:11blanket?

28:13for the clarifiers to keep all the

28:15solids without wash out.

28:18So at 2 MGD

28:21I go up to my curve I can say I need 4T

28:23of clear water space. Well if I have 8

28:27foot total sidewater depth of the

28:28clarifiers that means my sludge blanket

28:30can be 4T deep before I at 2 MGD before

28:33I start blowing out solids. And you can

28:36look at that for any given flow rate.

28:37And what you find is that at 7.7 MGD,

28:41you need 8 foot of clear water depth.

28:42And the clarifiers are only

28:478 ft tall.

28:49So

28:51I can't no matter what I do at 7.7 MGD,

28:58I run out of space for my sludge blanket

29:00and I'm going to have solids wash out.

29:03So

29:05there is no like easy fix for that uh or

29:09anything we can do um on the biology

29:12side to stop that from happening.

29:16Uh what I can do potentially and it cost

29:22is

29:26if I have a twoft sledge blanket

29:31and

29:35that means I need 6t of clear water

29:37depth and I can only go up to 4t. If I

29:41can take my two foot sludge blanket,

29:43densify it, compact it down into one

29:46foot, well then I can go up to this 7

29:49foot

29:51of clear water depth and go from four to

29:54almost, you know, 5 1/2 mgd of capacity

29:58before I start experiencing wash out. So

30:06what that looks like

30:10is

30:13when high flows come through. If I had a

30:15twoft blanket before, I would lose some

30:18solids. I might be able to maintain them

30:20a little bit better, make it a little

30:22more resistant to scouring. But once I

30:24hit a certain value, a certain flow

30:26rate, no matter what I do, I'm I'm

30:28blowing solids out of these clarifiers.

30:38Okay. So, if I want to identify the

30:41sludge, there's a couple complications

30:44with it. Um,

30:47I have to first purchase one of these

30:49pieces of equipment that uses uh

30:52cyclones to separate

30:56lighter matter in the sludge from denser

30:58matter in the sludge. And then when I

31:00waste out of my process here,

31:04I'm only wasting

31:06the the light stuff and I keep the

31:08heavier stuff in in the process tank.

31:13Uh

31:16these aren't calculations that are

31:19textbook in terms of if I add one of

31:22these, how dense can I get my sludge?

31:25because a lot of it relies on the

31:27bacteria of the sledge itself and the

31:29influent characteristics of the

31:30wastewater.

31:32And so

31:33there's a a high cost.

31:37Uh we we would have to in install uh

31:41infrastructure piping to make this

31:43system work. Um you can't just rent this

31:46unit and try it out for like a month and

31:48see if it works. It's that's uh a little

31:50more complicated than that. Um, so this

31:54path isn't really recommended uh for the

31:57facility and we kind of just have to

31:59live with those secondary clarifiers

32:01uh the way they are right now and really

32:03focus on the primary clarifiers if we're

32:05trying to squeeze a little more capacity

32:06out of the facility.

32:11Okay.

32:13So,

32:15um,

32:17gone over a lot of information, but I I

32:20really haven't even started to get in

32:21yet on, you know, what do we actually

32:23have to do at the facility to accept

32:24those future flows and loads that I

32:26talked about, knowing that we're out of

32:28capacity now. And, um,

32:32the secondary clarifiers are not ideal

32:34for the flows that we receive at the

32:35facility.

32:37Um

32:40so

32:42from a big picture

32:45uh

32:46what we looked at was uh okay we're

32:49going to look at these conventional

32:50processes the the MLE the A2O

32:52potentially the five-stage bird info. So

32:54I looked at the the sizing of all of

32:55those conventional processes and um I

33:00also looked at uh some a few advanced

33:02technologies uh that may that we thought

33:05may be a good fit here. And really what

33:07we uh zeroed in on was the the membrane

33:10bioreactors.

33:12And um they they are a more complex

33:15technology, but there's key benefits to

33:18the that system that we'll get into that

33:21uh that'll make that'll be self-evident

33:23as to why they were selected for kind of

33:25further evaluation.

33:29Uh but first things first is we got to

33:31get those uh secondary clarifiers

33:33straightened out. Um and and really what

33:36that consists of is uh constructing

33:39three new circular uh secondary

33:42clarifiers

33:44and uh that also comes with a new

33:47distribution box and a return uh waste

33:50act return and waste activated sledge

33:51pump station.

33:53And so in the figure here you'll see

33:55these uh three clarifiers distribution

33:57and a return sledge pump building.

34:05This

34:07is applicable for all of the

34:08conventional alternatives. If we go with

34:10the membrane bioreactors,

34:13you don't need the secondary clarifiers.

34:19Uh back to that future tertiary

34:21treatment that we would be looking at.

34:23Um

34:25typically uh what we will do is we'll

34:27put in cloth disc filters. The flow

34:33submerge the influent flow submerges the

34:35filter. Uh solids remain on the outside

34:38of the filter. Clean water flows to the

34:40inside and then out.

34:43Uh you can you dose your your metal salt

34:46upstream of these filters and they will

34:49uh that'll precipitate the phosphorus

34:51out. And once it's in a solid form, we

34:55can

34:57remove it via the the filtration

34:58barrier.

35:01Uh

35:02this process goes along with backwash

35:06pumps and um depending on the

35:10manufacturer those backwash pumps can

35:11either be inside or outside the

35:12filtration tank itself.

35:19Okay. So that MBR technology that I was

35:22talking about,

35:26instead of

35:29introducing my raw waste water to the

35:31bacteria, letting the bacteria

35:34eat what we don't want in there, and

35:38then settling the bacteria out in the

35:39secondary clarifiers via gravity, we can

35:43actually

35:45uh use a ultrailtration membrane

35:50and uh pump clean waste water from the

35:54mixed liquor through these membranes and

35:57then and then downstream. And what that

36:00does is it it creates a much better

36:02effluent quality. It removes those

36:04secondary clarifiers that I was showing

36:08a couple slides ago. Um,

36:12it also serves as the filter itself for

36:14that tertiary filtration process. So

36:16that that the membranes could

36:17potentially remove not only the the

36:19secondary clarifiers but also the the

36:21future uh phosphorus filtration process.

36:25Um, another benefit, since I'm not

36:27relying on gravity to set out my settle

36:29out my bacteria,

36:31I can uh increase the amount of bacteria

36:35I have in a given unit volume, which

36:39means my mixed liquor is what everyone

36:41talks about, right? I can get my mixed

36:42liquor uh concentrations uh jacked way

36:45up, and that ultimately makes the the

36:48aerration tanks that are required

36:51smaller.

36:54And because of all those uh benefits and

36:58concrete that we can save on by by

37:01installing these membranes, even though

37:02they are more complex and uh require

37:05more uh mechanical equipment, they they

37:08have they have a lot of uh potential

37:09cost savings.

37:14All right.

37:17The Killingly facility

37:20has this roughing filter. This is

37:22upstream of the activated sludge or the

37:25aeration tanks.

37:27And uh how this works is the waste water

37:31gets uh irrigated on the top of it flows

37:34over uh

37:37fixed film grow bacteria on them and as

37:40the as the waste water flows the the

37:42bacteria

37:43eat what we don't want out of the eat

37:46what we don't want in there. Um,

37:50it reduces the organic load and the

37:51ammonia load prior to getting into the

37:53aeration tanks and

37:57it's

37:58it needs refurbishment. It was last

38:02upgraded around 25 years ago. So, if we

38:05want to if we want to take credit for

38:08the the treatment occurring in this, we

38:11really need to bring it up to standard.

38:14And um it serves

38:18uh it it does the same treatment as one

38:21aation tank. So if I keep this, I

38:24upgrade it, I need one less aation tank

38:27uh in in my uh uh

38:32in my facility.

38:35So

38:39with all that I want to introduce the

38:41three alternatives that I am going to

38:44take a deeper dive uh into and and do a

38:48full life cycle cost analysis. So so

38:51talking about um what are all the

38:53capital uh costs associated then also

38:56what are those life cycle costs.

39:00Uh the first

39:03uh process is a conventional process

39:06where we don't

39:08upgrade the trickling filter. So you

39:12still go through the primary clarifiers

39:14as they are now. We upgrade the

39:18secondary process to an A2O where we

39:22have the anorobic zone followed by our

39:24anoxic and our aation zone and we leave

39:27space for that future B info process. uh

39:30should it's should it be required

39:32and then we flow through the uh new uh

39:36circular secondary clarifiers

39:39which then uh

39:42get pumped into a tertiary filtration

39:44process. And so this is what that

39:47facility uh requirements are for those

39:51uh future 20-year uh flow and load

39:54projections that I went out over

39:55earlier.

39:58Um the next alternative that I am

40:01looking at is

40:04keeping the trickling filter

40:09flowing to the A2O process leaving space

40:12for my BNFO and then also having the

40:15disk filtration downstream.

40:18And then the the third alternative that

40:21I am looking at is the MBR technology.

40:27Some of the nuance to the MBR technology

40:29is we do have to add a fine screening

40:32step downstream of the primary

40:34clarification instead of the roughing

40:36filter. We have a decreased

40:40uh aation uh tank

40:44and MLE process.

40:46We leave space for the future an oic

40:48zone. The the membranes themselves are

40:52airrated so we don't need that that

40:54rearration zone of the barnfo process in

40:56the future. Um

40:58the membranes are expensive like really

41:01expensive. So uh the the approach is to

41:07use

41:09the existing secondary clarifiers that

41:11we're abandoning as uh flow equalization

41:14to dampen out the peak flows going to

41:16the membranes decreasing our capital

41:18cost on the membranes. Since the

41:20membranes are airrated continuously and

41:23we have oxygen in our return sludge,

41:26high amounts of oxygen in our return

41:28sludge, we do want to de oxygenate the

41:31uh the RAZ before sending it into the

41:34biological phosphorus removal anorobic

41:36zone.

41:38So

41:42that's the big picture process flow.

41:45What does that mean in terms of uh

41:47amount of tankage required, level of

41:49treatment? Well, this is a a summary

41:51slide here to for you guys to take all

41:53in. Um that first process where we don't

41:58uh take credit for the roughing filter.

42:01We're talking about three new aation

42:03tanks the same size of the existing with

42:06the three new secondary clarifiers and

42:08that tertiary disc filtration.

42:11Um the second one where we keep the

42:14roughing filter

42:17the uh that does allow me to only

42:20install two new aation tanks uh similar

42:24in size to the existing. I still need

42:26the three secondary clarifiers. I still

42:28need the tertiary disc filters and I do

42:31have to rehab the uh the trickling

42:33filter.

42:36Uh the last alternative, the MBR, the

42:39advanced technology one. We I only need

42:40one aation tank. Uh I need new uh

42:45tankage to put my filters in and I need

42:49uh the new fine screen process. I like I

42:51said I the existing secondary clarifiers

42:54will be repurposed for the flow

42:55equalization.

43:00Uh effluent quality is listed for each

43:04process. We do get better effluent

43:07through the ultra filtration just by uh

43:10the the fear uh the the the fact that

43:14we're um

43:17uh just have a smaller barrier of the

43:19solids uh and the liquid process. Um

43:24>> hang on a minute, Dylan. We lost the

43:26visual.

43:36Let me know when you get it back up. I

43:37just changed the slide to the layouts.

43:48>> Yeah, we're working on it.

43:52>> Any questions while we're taking this

43:54break here? I know I've gone through a

43:55lot so far and when it's in person, it's

43:57a lot easier to interrupt me. Um,

44:10>> Dylan, do all the three options include

44:13tertiary treatment?

44:18>> No. The me M MBR process takes the place

44:22of the tertiary treatment. You get you

44:24get better quality from the MBR. you

44:27just don't need that extra tertiary

44:30treatment. You the the physical

44:32separation of the liquids and solids. Um

44:37>> so essentially in the diagram the disc

44:40filters are the tertiary treatment that

44:42you're talking

44:43>> correct. Yeah.

44:44>> Correct. Okay. Yeah.

44:49And it is a little

44:51uh maybe um misleading thinking that

44:54because you have the tertiary treatment

44:56being the disc filters that you have

44:58better effluent quality.

45:00>> We got the slides back now. Okay. But go

45:02ahead.

45:02>> Okay.

45:03>> Yeah, but the the membrane is actually a

45:05much finer filter than what those disc

45:07filters are.

45:09Okay. So

45:13what I'm showing now is

45:17the uh

45:20alternative where we're demoing the

45:22roughing filter. Uh we'll need a new

45:24aation tank splitter structure. Uh each

45:27tank here is sized in similar fashion to

45:31the existing. Um but this is to give you

45:35a a sense of what the scale is of uh you

45:38know one new aeration tank or three new

45:40aation tanks, right? Um

45:43uh your your three new secondary

45:45clarifiers and then your space for the

45:48return sludge pump building and uh

45:50tertiary filtration uh which would be uh

45:52phased in.

45:56uh if I rehab that filter,

46:00one less aation tank. Um

46:04otherwise uh very similar process flow

46:07and and upgrades uh required. The the

46:10question really becomes you know does it

46:14cost more to rehab that filter versus

46:18the aeration tank?

46:23And then the the last alternative

46:27is the MBR process where we only have

46:30the one new aeration tank. We do have to

46:33put a fine screen uh process in and

46:38uh we will need uh space for the fil

46:42filters to go themselves, the ultra

46:44filters, the membranes. Uh and then uh

46:48it actually requires a fairly large um

46:52process building associated with it so

46:54that uh you can have place for all the

46:56pumps and mechanical equipment

46:57associated.

46:59Um

47:04so

47:07from a treatment and a upgrades required

47:12perspective this is what we're looking

47:14at. Uh I am currently

47:17um

47:19running down all of the costs, you know,

47:21what does it actually cost to, you know,

47:23to put these to implement each one of

47:25these. Uh the membranes have to be

47:27replaced after 10 years. They they take

47:29chemicals to clean them. And so there's

47:31a lot of operational costs that that go

47:33into that process. It's not a slam dunk

47:37uh that it's going to be the best just

47:38because it is the best on the site plan.

47:40Uh but I look at both the monetary and

47:42non-monetary

47:44uh benefits of all the alternatives

47:48and you know that's kind that's where

47:50I'm at now is uh you know continuing

47:53this uh work with the operators at the

47:56facility on their primary clarification

48:00um you know assistance

48:03uh doing that detailed cost analysis of

48:06each of the alternatives and then uh the

48:09goal is to have another workshop uh with

48:13the the facility staff and um develop a

48:20report that summarizes everything that

48:21I've done.

48:24So with that, uh thank you for giving me

48:26this time to present to all of you. Uh

48:29and um yeah, let me know if you have any

48:32questions. I'm happy to sit sit around

48:35and talk.

48:42Okay, thank you Dylan. Uh, one of first

48:45one question I had when you were talking

48:47about it um on the roughing filter, you

48:50said it provides some reduction

48:53in the uh BOD, but like how how much of

48:58a reduction

49:00and is it you like is it really

49:04functioning? Do we have a good way to

49:06measure that too? I guess would be the

49:08another, you know, related question.

49:12>> So the the complicated thing with the

49:14the roughing filter is the the bacteria

49:17gets mixed in with the primary effluent

49:19prior to going through the roughing

49:21filter. And when you start sampling

49:26uh mixed liquor for BOD,

49:29uh the the BOD test picks up all the

49:32bacteria in the in the sample and like

49:35you have you see like really really high

49:37BOD values. So it's it's very tough to

49:42identify, oh, this went in and this went

49:44out of the roughing filter. Um I have a

49:47biological process model that I can use.

49:51uh that's uh that's based on the mass

49:54balance of the facility where I can

49:58quantify the the BOD removed uh through

50:02it. Um and

50:05when I look at it, I don't really look

50:06at it as like what came in, what came

50:08out, how much was reduced going into the

50:09aeration tanks. I look at it from a a

50:12whole process of like um what does that

50:16resulting load that comes out of it do

50:18to the mass of bacteria in the mixed

50:20liquor tanks? And so it's not

50:23necessarily in terms of the the BOD in

50:26terms of a certain pounds per day that

50:28that's removing. It's it's more of um

50:31you know how does that decrease the uh

50:33the amount of bacteria that's floating

50:35in the aeration tanks.

50:43So [snorts] when you first did the

50:45presentation um the first time you had

50:48made a comment that you wouldn't build

50:50another one probably I mean is this

50:52there are they not really getting built

50:54these days? Is it kind of an outdated

50:56technology or

51:00>> Yeah, it's it's uh uncommon to have a

51:05roughing filter in the process flow of

51:08uh a new facility unless the the

51:10wastewater characteristics

51:13um were

51:16very uh and really the effent goals too.

51:18So like it's more like what what the

51:21tricculine filter does is it takes out

51:22the soluble BOD, right? And um it's

51:28really good for really heavily organic

51:30loaded stuff that may not have like

51:32nitrification requirements downstream.

51:35Um, so I wouldn't put this in at uh say

51:38this facility

51:40um if we were starting from scratch

51:47and we don't

51:51it's not it's not common.

51:56>> Thank you Dylan. Uh if you were starting

51:59from scratch, what technology would you

52:01recommend?

52:05Uh that would be alternative one. Uh a

52:10um

52:12and I I would do I would do the same I

52:16would really just do the same evaluation

52:17without the roughing filter alternative

52:19because um as

52:23uh the technology advances that that

52:26ultra filtration technology advances

52:28we're starting to see it more mainstream

52:30um in treatment plants and especially

52:33where you have uh really stringent

52:35limits and potential um you know reuse

52:39uh requirements uh of the wastewater. Um

52:44so it's it really comes down to that

52:47analysis of

52:50does it cost more to construct all the

52:52concrete for the secondary clarifiers

52:54and the

52:57um tertiary filtration process.

53:00uh if if I didn't have to have a

53:02tertiary filtration process, I would

53:05almost like say it's a slam dunk that

53:07you would just put in the conventional

53:08process with the secondary clarifiers.

53:10The fact that I have to have a whole

53:12another building and uh tertiary

53:14filtration in the future, um

53:18that really is what could could be the

53:20tipping point of uh why the the

53:22membranes would be more beneficial.

53:26So, it may be more cost effective to

53:28install the tertiary or at least plan

53:31for it at this point as opposed to

53:34not planning for it. Is that a true

53:36statement?

53:40>> Um,

53:47can you repeat that question, please?

53:49Would it be more beneficial to plan for

53:52the tertiary treatment at this point as

53:54opposed to not planning for it?

53:58Um

54:05if you if you are going with the

54:08conventional process

54:10you have to have the tertiary filtration

54:12at some point. Uh you will have to plan

54:14for it. Um

54:17if we do the cost anal if I do the cost

54:20analysis and I it it appears that the

54:23membrane technology

54:26uh is more cost effective

54:30then uh the the that extra disc

54:34filtration that just goes away. You you

54:36you build the membranes now it does what

54:39the filters will do 10 years from now.

54:41Um, and you don't even have to think

54:44about putting in the disc filters. It's

54:48it's much more superior filtration

54:50process.

54:52>> Okay. Thank you. Um, last question I

54:55have for you. Um,

54:58any rough idea on how long it would take

55:00you to finalize numbers and come up with

55:03the report? I'm not putting you on the

55:05spot. I'm just trying to get a general

55:06timeline.

55:09Um,

55:11I believe we're looking at the

55:14end of October

55:17to regroup with the workshop and present

55:20costs.

55:25That's the goal.

55:26>> Okay. Thank you.

55:33>> Does anyone else have any questions?

55:37So, I guess what it looks Oh, Joe.

55:42>> Hi, Dylan. Quick question. Um, is there

55:45a Connecticut plant or a Massachusetts

55:47plant that currently uses the MBR um

55:52that has at least five or six MGD daily

55:55flow?

55:58>> Off the top of my head, I'm not sure. I

56:00have to I can connect with the

56:03manufacturers. I did just complete a

56:07design for a Massachusetts plant in

56:10Barnstable of similar flow uh for the

56:13membranes and um it's uh it's not a

56:20um

56:22like uh it's a proven technology.

56:26>> Okay. Cuz uh cuz that's just my concern

56:28that um when our flows are getting up

56:30there if it could handle our flows. So

56:33be nice to have a proven plan.

56:35>> Yeah.

56:40>> So on the the disc filters could

56:42potentially be put in in a second phase

56:46then.

56:46>> Correct. Yeah.

56:50>> Yeah. So when I when I do my cost

56:52analysis, I'm going to use that 10-year

56:54time frame that I I mentioned in the

56:56presentation and um I'm going to develop

56:59what those look I'm going to say, hey,

57:02what would the capital cost be right now

57:03to build a disc filtration process? I'll

57:07uh escalate that to 10 years from now

57:09and then I'll add that into the you know

57:11the the 20-year life cycle cost is a a a

57:1510year cost.

57:20Okay, thank you.

57:22Any any more questions?

57:26Okay, thanks Dylan. Yeah, Dave.

57:30Uh, excuse me. Uh, Dylan, um, for my

57:33benefit, if u, I think I'm a little

57:35confused on the disc versus the

57:38membrane, they are they similar? They

57:41achieve similar results. One's just more

57:43efficient. Or could could you explain

57:45the difference between the two, please?

57:49Yeah. Yeah. So, the uh the disc filters

57:53are going to have like a a cloth uh uh

57:58media and um

58:02the

58:04diameter of the the pores on that media

58:07are much larger than what the diameter

58:11of the pores on the membrane are. So,

58:13uh, essentially solids that can get

58:15through the disc filters won't be able

58:16to get through the membranes.

58:20>> Okay. Thank you.

58:29>> Okay. Thank you, Dylan. We look forward

58:32to the uh completed report.

58:37>> You're welcome.

58:43Okay, that completes item A.

58:46>> Yep.

59:05Well, I think before we see the um you

59:07know the cost associated with it, it

59:09would be kind of premature to take a

59:12action on it other than we could just

59:16give a general endorsement that we we

59:19could, you know,

59:21>> that he's we feel he's heading in the

59:23right direction.

59:24>> That was my thought. Yes.

59:27>> And what is the committee, you know,

59:29what do people think about it?

59:49>> It's hard to have an opinion when we

59:51don't look at the costs, but it's uh

59:54it's

59:55desirable to see that we have multiple

59:57options to be looking into. So, I'll

1:00:00have to better equip myself with with

1:00:02some of this in the interim, but I

1:00:05appreciate your time for sure.

1:00:18Joe,

1:00:21Jacob, No.

1:00:24I mean, I think we're heading in the

1:00:26right direction with, you know, getting

1:00:28some plans drafted and getting the

1:00:29price.

1:00:35Okay, that being said, uh, move on to

1:00:40item B, discussion of possible action on

1:00:43amending the resolution to relax the

1:00:45moratorum.

1:00:53Now, we got copies of that, but it's

1:00:55still um

1:01:00it's still labeled as uh

1:01:03the third amendment and it's doesn't

1:01:06have the mention of the what was

1:01:10actually the third amendment in it.

1:01:25Yep, correct. We can certainly make

1:01:27those modifications.

1:01:29Um,

1:01:30I believe this would need to go through

1:01:33legal review before we finalize it, but

1:01:36I don't know if there are any other

1:01:37comments besides those.

1:01:43Yeah, I thought the rest of it looked

1:01:45pretty good except, you know, we just

1:01:47have to be clear in acknowledging that

1:01:48we've already approved um categories 16

1:01:52and 17.

1:01:55But the um you know the table

1:01:59was helpful in kind of summarizing

1:02:03how this um how the

1:02:07capacity is going to be um encumbered.

1:02:15So, do you think you can get it um

1:02:19get that modified to update the

1:02:22beginning portion of it and get it to

1:02:24legal?

1:02:25>> Absolutely. It's not a problem. If

1:02:27again, if those are your only comments,

1:02:29that's simple enough to do. Um just need

1:02:32a motion to that effect and authorizing

1:02:35uh the expenditures.

1:02:48So, does anybody else have any um other

1:02:52comments about it?

1:02:57Pat, just as a reminder about the typo

1:02:59that was in there for the BOD and the

1:03:01TSS.

1:03:24So, is there a motion to uh well

1:03:29to have it updated and then sent to

1:03:32legal that the ex the motion would be

1:03:36needed for the expense of legal? Is that

1:03:38what

1:03:39>> right? Because I mean I can send it to

1:03:42legal with your comments and they can

1:03:44incorporate it. That way we don't have

1:03:46to reproduce it and there might be a

1:03:49different way of phrasing it or

1:03:50something. and it might save some time,

1:03:52but that's up to you.

1:03:56>> Well, did the attorney formulate the

1:03:57last uh a

1:04:00>> uh we did in house, Brian Poa, as well

1:04:03as everybody else, but did go through

1:04:05legal for final review.

1:04:08>> But could this be updated then in house

1:04:10and then sent to the attorney?

1:04:12>> Absolutely. Having to update it?

1:04:14>> Absolutely.

1:04:19Is there a motion

1:04:21or other?

1:04:23>> I'll make a motion to

1:04:26update the final draft for legal review

1:04:30and then um

1:04:33provided to us at the next meeting for

1:04:35consideration for approval.

1:04:39I'll

1:04:42>> Are we confident we'll have a response

1:04:44from legal by the time our next

1:04:46scheduled meeting will take place?

1:04:52>> I think it's four weeks from tonight the

1:04:54next meeting

1:04:56>> because

1:04:57>> I did not ask that question but I would

1:05:00still need authorization to expend

1:05:02funds.

1:05:06Any

1:05:10So we have a motion and a second. Any

1:05:12further discussion?

1:05:15Yes.

1:05:24Hearing no further discussion. Um all

1:05:26those in favor?

1:05:28I

1:05:29>> I

1:05:30>> I

1:05:31>> Okay, it's uh five to nothing unanimous

1:05:34to um approve uh a motion to the motion

1:05:38that was presented by Joe.

1:05:44Well, that the last item on the ag on

1:05:47this special meeting's agenda. So, um

1:05:52with that, we're off to item four.

1:05:57Is there a motion to adjurnn?

1:06:02>> Yeah, I'll make a motion to adjurnn.

1:06:05>> Second.

1:06:06>> Second.

1:06:08>> All those in favor? I I

1:06:10>> I

1:06:12motion

1:06:13passed and meeting is adjourned at 608.