Hollis Select Board Transparency Archive

Thanks, Joshua!

Dick Darling

Consulting Engineer

Water Quality and Compliance Services

From: Gildert, Joshua <[email protected]> Sent: Tuesday, June 23, 2026 7:49 AM To: [email protected] Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

Thanks Dick,

We will include wording in our approval letter regarding piping the bypass to be sure that the lead tanks can't accidentally be bypassed, but allowing removable spools/piping so media can be replaced.

You should see the approval letter by end of day.

Thanks,

Joshua Gildert, P.E.

Environmental Engineer

Drinking Water / Engineering and Water Resources/Engineering Review

(207) 215-7172 SOMPLAINTEXT

Maine Center for Disease Control and Prevention - Preserve ~Promote ~ Protect

From: [email protected] <[email protected] > Sent: Thursday, June 18, 2026 8:36 PM To: Gildert, Joshua <[email protected] > Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

EXTERNAL: This email originated from outside of the State of Maine Mail System. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Hi Joshua,

If required, we can pipe the bypasses such that they cannot be used unless/until either the PFAS media or the arsenic media require rebedding. The concept, as I'm sure you know, is to continue treatment for both PFAS and Arsenic when one or both systems need the media replaced.

Dick Darling

Consulting Engineer

Water Quality and Compliance Services

From: Gildert, Joshua <[email protected] > Sent: Thursday, June 18, 2026 3:55 PM To: [email protected] Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

Hi Dick,

I think one final item to address before we issue our letter:

Will the bypass valves on the GAC and arsenic tanks have removable spool pieces and those spool pieces would only be installed in the event of media replacement or maintenance?

Thanks,

Joshua Gildert, P.E.

Environmental Engineer

Drinking Water / Engineering and Water Resources/Engineering Review

(207) 215-7172 SOMPLAINTEXT

Maine Center for Disease Control and Prevention - Preserve ~Promote ~ Protect

From: [email protected] < [email protected]> Sent: Thursday, June 4, 2026 10:28 AM To: Gildert, Joshua < [email protected]> Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

EXTERNAL: This email originated from outside of the State of Maine Mail System. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Hi Joshua,

Ther should be no problem with iron or manganese affection the life of the carbon. While some iron will be adsorbed, the concentration is so small, the effect will be negligible. The Manganese will pass right through.

Dick Darling

Consulting Engineer

Water Quality and Compliance Services

From: Gildert, Joshua < [email protected]> Sent: Wednesday, June 3, 2026 3:36 PM To: [email protected] Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

Hi Dick,

Another question:

With the iron filter proposed after the PFAS treatment do you foresee any issues with the iron and manganese reducing the lifespan of the PFAS media? Per the water quality data it looks like both iron and manganese are well below the MCL, but wanted to get your thoughts.

Thanks,

Joshua Gildert, P.E.

Environmental Engineer

Drinking Water / Engineering and Water Resources/Engineering Review

(207) 215-7172 SOMPLAINTEXT

Maine Center for Disease Control and Prevention - Preserve ~Promote ~ Protect

From: [email protected] < [email protected]> Sent: Tuesday, May 26, 2026 12:08 PM To: Gildert, Joshua < [email protected]> Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

EXTERNAL: This email originated from outside of the State of Maine Mail System. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Thanks!

From: Gildert, Joshua < [email protected]> Sent: Tuesday, May 26, 2026 12:02 PM To: [email protected] Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

Hi Dick,

Thanks for providing the new documentation. No need to file a new application, I will add the new filter cutsheet into the application packet.

Thanks,

Joshua Gildert, P.E.

Environmental Engineer

Drinking Water / Engineering and Water Resources/Engineering Review

(207) 215-7172 SOMPLAINTEXT

Maine Center for Disease Control and Prevention - Preserve ~Promote ~ Protect

From: [email protected] < [email protected]> Sent: Tuesday, May 26, 2026 11:58 AM To: Gildert, Joshua < [email protected]> Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

EXTERNAL: This email originated from outside of the State of Maine Mail System. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Hi Joshua,

We will replace the filter we spec'd with the Pentair/Pentek DGD-5005 155357-43, which is NSF approved (spec sheet attached.)

Do I need to file a new System Chang Application?

Dick Darling

Consulting Engineer

Water Quality and Compliance Services

From: Gildert, Joshua < [email protected]> Sent: Tuesday, May 26, 2026 11:37 AM To: [email protected] Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

Hi Dick,

I wanted to follow-up on this. Still no response from Pentair.

Thanks,

Joshua Gildert, P.E.

Environmental Engineer

Drinking Water / Engineering and Water Resources/Engineering Review

(207) 215-7172 SOMPLAINTEXT

Maine Center for Disease Control and Prevention - Preserve ~Promote ~ Protect

From: Gildert, Joshua Sent: Friday, May 15, 2026 7:41 AM To: '[email protected]' < [email protected]> Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

Hi Dick,

Still no response to my original email or follow-up to Pentair. If you do have an alternative filter cartridge you would like to use that may be the easiest path forward.

Thanks,

Joshua Gildert, P.E.

Environmental Engineer

Drinking Water / Engineering and Water Resources/Engineering Review

(207) 215-7172 SOMPLAINTEXT

Maine Center for Disease Control and Prevention - Preserve ~Promote ~ Protect

From: [email protected] < [email protected]> Sent: Wednesday, May 13, 2026 9:27 AM To: Gildert, Joshua < [email protected]> Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

EXTERNAL: This email originated from outside of the State of Maine Mail System. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Good morning Joshua,

If the Pentair filter cartridge is not NSF approved, we will find/use on that is.

The Bubble up Radon removal system is the R.E. Prescott CBU-415.

Dick Darling

Consulting Engineer

Water Quality and Compliance Services

From: Gildert, Joshua < [email protected]> Sent: Wednesday, May 13, 2026 8:56 AM To: [email protected] Cc: Matt Morrill < [email protected]>; 'Carl Helsel' < [email protected]>; Michael Harvey < [email protected]>; Walter Longfellow < [email protected]>; [email protected] Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

Thank you Dick,

I have sent an email to Pentair to confirm NSF compliance of the filter. We will need documentation from the manufacturer or NSF to confirm compliance.

Can you please confirm which size Bubble-Up system is intended to be installed?

Thanks,

Joshua Gildert, P.E.

Environmental Engineer

Drinking Water / Engineering and Water Resources/Engineering Review

(207) 215-7172 SOMPLAINTEXT

Maine Center for Disease Control and Prevention - Preserve ~Promote ~ Protect

From: [email protected] < [email protected]> Sent: Monday, May 11, 2026 2:47 PM To: Gildert, Joshua < [email protected]> Cc: Matt Morrill < [email protected]>; 'Carl Helsel' < [email protected]>; Michael Harvey < [email protected]>; Walter Longfellow < [email protected]>; [email protected] Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

EXTERNAL: This email originated from outside of the State of Maine Mail System. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Hello Joshua,

Below are the answers to your questions and I have attached the materials noted.

1. Please provide a PE stamp for the project if cost exceeds $10,000. If cost is less than $10,000 then a cost estimate from the installer is sufficient.

A stamped copy of the System Change Application with a stamped copy of the system layout are attached

2. Please provide a copy of the HHE-200 and hydraulic load calculations for the septic system showing the system is capable of accepting the additional volume from backwash.

Attached

3. Please provide the raw water quality data that was indicated on the change application.

Attached

4. What is the minimum tank volume that will be in the atmospheric storage tanks when the pump switch activates?

The storage tanks will have a minimum of 325 gallons of water when the booster pump in the CBU-415 unit activates to provide flow to fill the storage tanks. The high level shut off will occur when the storage tanks contain 375 gallons of water.

5. Will sample taps be installed after the UV units?

Yes. The system layout has been changed to reflect sample taps after the UV units.

6. What are the expected media changeout intervals?

The first tank containing 2.5 ft3 of granulated activated carbon used for PFAS removal should last at least 2 years at the flow level of 1,275 gal/day used for the septic system design. With 2 tanks operating in series, the lead tank can be isolated and rebedded with no loss of treatment. Semi-Annual Monitoring will detect any bleed-through from the first tank and allow rebedding while the second tanks continues to provide treatment.

ASM-10 is an absorptive resin, and water testing every 6 months will dictate when it needs to be changed. That is why we have a back-up system there; when the first tank is done, the second one will pick up the slack until the new one gets installed. Given the pretreatment, I would expect it to last 2-4 years. But again, that's where the semi-annual testing comes into play; it needs to happen.

The CGS Mineral is a regenerative and self-cleaning media and should last based on the manufacturer's recommendation to change it out every 8 years. Annual testing will also dictate when this unit needs the mineral swapped out.

The SBG-2 Mineral has a longer lifespan, the manufacturers recommend replacement every 8 years. Annual testing will indicate when the media needs to be changed, as this also depends on water usage. It is a regenerative mineral that self-cleans, preserving a longer lifespan.

Calcite mineral service is provided annually to replenish the mineral. The calcite is absorbed into the water and slowly decreases the mineral level. There is more than enough mineral in the tank to last 1 year. This requires yearly service for replenishment. This also highly depends on water usage and annual testing will dictate whether one year or 6 months is required.

7. What is the model # of the Clack brine tank that will be installed?

The tank will be model G21840[*]B1C00 (The asterisk denotes the color, which we don't know)

8. Please provide documentation showing NSF compliance and model number for the proposed filter housing.

Attached for VIQUA AWP40B-V

9. What is the model # of the Pentek 5 micron filter will be used?

The Pentek filter is model ECP5-BB / 255490-43

10. Please provide documentation showing NSF compliance for the 5 micron filter.

Several vendors state that the Pentek filter is NSF approved. A link to the website of one of the vendors is; https://www.servapure.com/Pentek-255490-ECP5- https://www.servapure.com/Pentek-255490-ECP5-BB-Pleated-Cellulose-Polyester- 45-x-10-5-Micron_p_1515.html

11. Which model of Air Pump will be installed?

The Air Pump will be the AP-1 110V pump.

12. It does not appear that the NSF certification provided for the atmospheric storage tanks includes the trade name of the tank specified. Please provide documentation showing compliance.

The tanks specified are Specialty Water Tanks/Free Standing Tanks listed on the NSF Sheet that was included in the original application.

13. Please provide documentation showing NSF compliance for the RE Prescott Bubble Up system.

The documentation provided for the CBU-415 states that the unit is constructed from NSF certified components. We have specified this unit, and it has been approved for multiple systems including Deer Ridge MHP (PWSID# ME0001194) and Raymond Woods Townhouses (PWSID# ME0092307). I have attached the approval letters for those two projects that reference the CBU-415 in the approvals.

14. Per EPA guidance a 3" pipe diameter for the radon vent is required. The diagram indicates a 3" outlet, but the change application notes a 2". Please confirm.

The System Change Application has been changed to show that the outlet pipe will be 3" PVC.

Please contact me with any other questions.

Dick Darling

Consulting Engineer

Water Quality and Compliance Services

From: Gildert, Joshua < [email protected]> Sent: Sunday, May 10, 2026 9:53 AM To: [email protected] Subject: RE: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

Hi Dick,

I have a few follow-up items to be resolved before proceeding with my review:

1. Please provide a PE stamp for the project if cost exceeds $10,000. If cost is less than $10,000 then a cost estimate from the installer is sufficient. 2. Please provide a copy of the HHE-200 and hydraulic load calculations for the septic system showing the system is capable of accepting the additional volume from backwash. 3. Please provide the raw water quality data that was indicated on the change application. 4. What is the minimum tank volume that will be in the atmospheric storage tanks when the pump switch activates? 5. Will sample taps be installed after the UV units? 6. What are the expected media changeout intervals? 7. What is the model # of the Clack brine tank that will be installed? 8. Please provide documentation showing NSF compliance and model number for the proposed filter housing. 9. What is the model # of the Pentek 5 micron filter will be used? 10. Please provide documentation showing NSF compliance for the 5 micron filter. 11. Which model of Air Pump will be installed? 12. It does not appear that the NSF certification provided for the atmospheric storage tanks includes the trade name of the tank specified. Please provide documentation showing compliance. 13. Please provide documentation showing NSF compliance for the RE Prescott Bubble Up system. 14. Per EPA guidance a 3" pipe diameter for the radon vent is required. The diagram indicates a 3" outlet, but the change application notes a 2". Please confirm.

Thank you,

Joshua Gildert, P.E.

Environmental Engineer

Drinking Water / Engineering and Water Resources/Engineering Review

(207) 215-7172 SOMPLAINTEXT

Maine Center for Disease Control and Prevention - Preserve ~Promote ~ Protect

From: [email protected] < [email protected]> Sent: Monday, May 4, 2026 3:00 PM To: [email protected]; Ralph Wesinger < [email protected]> Cc: Matt Morrill < [email protected]>; 'Carl Helsel' < [email protected]>; Walter Longfellow < [email protected]>; Michael Harvey < [email protected]> Subject: Documentation for System Change Application for the Hollis Town Office (PWSID# ME0092920)

EXTERNAL: This email originated from outside of the State of Maine Mail System. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Here is the remaining documentation for the SCA for the Hollis Town Office (PWSID# ME0092920)

Dick Darling

Consulting Engineer

Water Quality and Compliance Services