HomeMy WebLinkAbout028_EmailDEQAccessCoordinationM-371Bobby Egeberg
From:Sean Potkay <spotkay@simkins-hallin.com>Sent:Friday, February 28, 2025 1:00 PMTo:Fry, KateCc:Jim Sullivan; Chris Naumann; Bobby EgebergSubject:Re: Simkins Hallin - Northpark (Bozeman Solvent Site Dewatering) CAUTION: This email originated from outside your organ ization. Exercise caution when opening
attachments or clicking links, especially from unknown senders. Kate/Jim, As part of our site plan review for Tracts 2B & 4B of C.O.S. 2153A we've been asked by the City of
Bozeman to provide access to the well (M37) that sits on Tract 2B of our site. Our site plan shows largely
impervious paving throughout the project outside o f the area in and around the existing well. We do show gravel installed all the way to the well so there will be a drivable path to test the well into the future. As part of the Site plan approval process, they would lik e to see either an access agreement or an easement
to get to the well. Our preference is an access agreem ent with DEQ and Tasman to allow access to the
site into the future to perform testing of the water in the well for monitoring of the controlled groundwater
site. (Bozeman Solvent Site) R eading the comment from the city we interpret that th ey would like a formal
agreement showing a means of access for future testing, so I wanted to get the conversation started and
have CC'd our civil team as well as they are driving th e site plan process with the City of Bozeman. Please add any additional team members on your end to the conversation that need to be included in order to move this process along. Best, Sean Potkay Simkins-Hallin 326 N. Broadway Bozeman, MT 59715 TEL O: 406-586-5495 TEL C: 406-209-1939 spotkay@simkins-hallin.com From: Fry, Kate <kfry@mt.gov> Sent: Tuesday, March 19, 2024 12:03 PM To: Sean Potkay <spotkay@simkins-hallin.com> Cc: Jim Sullivan <jsullivan@tasman-geo.com>; DEQ QuickReq <deqquickreq@mt.gov>; Christopherson, Sarah <Sarah.Christopherson@mt.gov> Subject: RE: Simkins Hallin - Northpark (Bozeman Solvent Site Dewatering) Hi Sean, I’ve attached a table that shows the depth to groundwater (and groundwater elevation) measured for the last 25-30 years from M-37. This table shows that groundwater tends to be shallower during June
2than December. This might be useful for scheduling purposes. Of course, dewatering is a non-issue if you don’t encounter the groundwater. One of the most comment treatments for PCE contaminated groundwater is granular activated carbon (GAC). This generally includes a series of two GAC filters. Periodic sampling is conducted pre-, mid-, and post-GAC filtration to determine if breakthrough has occurred. The filter size would depend on how much water you needed to treat, how quickly, and how it will be contained prior to treatment. Another option is land application (e.g., sprinkler irrigation). PCE is a volatile compound and breaks down when aerated. The option requires an appropriately sized area for the land application. Please obtain the landowner’s permission for the land application. Again, you would need to know how much water needs to be treated, how quickly, and if it needs to be contained prior to aeration. These are just a few options, and this email is not intended to suggest one over another. There may be other options available. Please continue to work with Christine Weaver or another DEQ permit writer to determine sampling requirements. Please let me know if you have questions. Regards, Kate Kate Fry | Senior Project Officer Superfund, AML, and Construction Bureau Waste Management and Remediation Division Montana Department of Environmental Quality Office: 406-444-6426 From: Sean Potkay <spotkay@simkins-hallin.com> Sent: Monday, March 18, 2024 1:25 PM To: Fry, Kate <kfry@mt.gov> Cc: Jim Sullivan <jsullivan@tasman-geo.com>; DEQ QuickReq <deqquickreq@mt.gov> Subject: [EXTERNAL] RE: Simkins Hallin - Northpark (Bozeman Solvent Site Dewatering) Kate, I reached out and had a chance to speak with Christine this morning on the DEQ requirements for PCE concentrations and discharge concentration amounts. Their Required reporting value is .7 for discharge which based on the data from well M-37 it is more likely than not that the concentrations would require abatement prior to discharge. Christine mentioned that you might have more information in regards to abatement options for removing or decreasing PCE
3levels to acceptable discharge levels. I’m hoping to wrap my head around the requirements if we do end up needed to do some kind of abatement with the dewatering and what I need to account for on a budget standpoint as well as figure out what kind of equipment would be needed for this. Any additional information would be helpful. Best, Sean Potkay Simkins-Hallin 326 N. Broadway Bozeman, MT 59715 TEL O: 406-586-5495 TEL C: 406-209-1939 spotkay@simkins-hallin.com From: Fry, Kate <kfry@mt.gov> Sent: Monday, March 18, 2024 8:52 AM To: Sean Potkay <spotkay@simkins-hallin.com> Cc: Jim Sullivan <jsullivan@tasman-geo.com>; DEQ QuickReq <deqquickreq@mt.gov> Subject: RE: Simkins Hallin - Northpark (Bozeman Solvent Site Dewatering) Hi Sean, Thank you for reaching out about the Bozeman Solvent Site. The North Park Tract 2B and 4B project you describe in your email below is within the Bozeman Solvent Site. The main contaminant of concern for the Bozeman Solvent Site is tetrachloroethene (PCE). Groundwater flow is from the south to the north. The closest Bozeman Solvent Site monitoring well to the project location shown provided is M-37. M-37 is located near the northwest corner of Tract 2-B on the east side of Mandeville Creek. If your construction activities are in the area of M-37, please contact DEQ to coordinate steps to prevent damage to M-37. M-37 is sampled annually in June as part of the Bozeman Solvent Site. Below is a table summarizing PCE concentrations in M-37 since 2017: M-37 June 2017 4.6 µg/L June 2018 4.2 µg/L June 2019 4.1 µg/L June 2020 <0.5 µg/L June 2021 3.6 µg/L June 2022 <0.5 µg/L June 2023 2.3 µg/L In August 2011, the Montana Department of Environmental Quality issued the Record of Decision (ROD) for the Bozeman Solvent Site. The ROD identified that the Bozeman Solvent Site site-specific clean up level (SSCL) for PCE in groundwater is 5 µg/L. The ROD identified the final cleanup remedy for this portion of the Bozeman Solvent Site as monitored natural attenuation (MNA). M-37 is part of the MNA monitoring program. As you can see, the PCE concentrations in M-37 are below the SSCL. The ROD does not identify construction requirements related to the Bozeman Solvent Site in this area. However, construction may require a dewatering permit. The depth to groundwater in M-37 is less than 10 ft. I believe the Construction Dewatering General Permit (CDGP) application requires
4the applicant to contact me regarding current groundwater plume conditions. This email may satisfy that requirement. Please note, the CDGP may have different requirements for PCE concentrations than the Bozeman Solvent Site SSCL prior to discharge under a CDGP. For addition information on the CDGP application process please contact Christine Weaver in DEQ Water Quality (406-444-3927 or CWeaver@mt.gov). In addition, your project is within the Bozeman Solvent Site Controlled Groundwater Area (CGWA). The CGWA is administered by the Montana Department of Natural Resources and Conservation (DNRC). The CGWA limits the type of groundwater wells that can be installed. Please contact DNRC for more information. This email only addresses concerns related to the Bozeman Solvent Site. Please let me know if you have questions. Regards, Kate Kate Fry | Senior Project Officer Superfund, AML, and Construction Bureau Waste Management and Remediation Division Montana Department of Environmental Quality Office: 406-444-6426 From: Sean Potkay <spotkay@simkins-hallin.com> Sent: Friday, March 15, 2024 5:07 PM To: Fry, Kate <kfry@mt.gov> Cc: Mark Theisen <mtheisen@simkins-hallin.com> Subject: [EXTERNAL] Simkins Hallin - Northpark (Bozeman Solvent Site Dewatering) Kate, Thanks for taking my call a bit ago and walking me through the Bozeman Solvent Site requirements. I have attached one of our most recent site plans showing our construction plans. We do as I indicated anticipate that we will have to dewater on the site in order to do our deep utilities during construction. The monitoring well that is closest to our project is well (M-37) which is in the Northwest Corner of the project. I indicated the well location with a green circle on the attached site plan PDF. Any additional information on the dewatering application and the process with Montana water quality department would be very much appreciated. Thanks for your help.
5Sean Potkay Simkins-Hallin 326 N. Broadway Bozeman, MT 59715 TEL O: 406-586-5495 TEL C: 406-209-1939 spotkay@simkins-hallin.com