This is an informational item and no action or recommendation is required at this time. More information is expected in late spring or early summer on this item regarding the model scenarios.

Study of the groundwater in the West Billings area has been the subject of several studies in the last 20 years. The City of Billings and Yellowstone County also conducted a flood study and looked at groundwater recharge in the area in 2011. The latest work by the staff of the Montana Bureau of Mines and Geology, Montana Technological University, was shared with the Planning Board at its meeting on 10/24/23 when the latest study work - Groundwater Investigation of the Billings Aquifer - was started. The project was originally nominated by the City of Billings through Boris Krizek of the Billings Public Works Environmental Affairs and was ultimately approved by the State. The objective of the study is to evaluate the groundwater conditions in west Billings and develop a conceptual groundwater model and identify the extent and source of nitrates.

The Groundwater Investigation team, led by Elizabeth Meredith, Hydrogeologist, Montana Bureau of Mines and Geology, Montana Technological University, has been working the last year and a half on collection of groundwater data as well as development of the model. Some City of Billings properties use wells for lawn watering, but the developed and agricultural areas outside the City in west Billings are highly invested in the groundwater for domestic use. The team has been utilizing both existing and new wells for data collection and monitoring for the study for both groundwater depth and fluctuations but also nitrate levels and other chemistry of the water. The study is designed to help forecast the need for future City services (water, sewer, and storm), and understand what ongoing permitting of development on wells and septic systems will result in, if groundwater availability fluctuates and decreases, and water quality also changes. 

While Yellowstone County is not involved in any process related to permitting of wells and septic systems through local subdivision regulations, this issue is of concern as development continues and wells and septic systems continue to be permitted by the State, and neighbors of the proposed developments ask questions and raise concerns about water quantity and quality.  As far as actual water rights are concerned, Yellowstone County leaves that authority to the DNRC.  As it pertains to water quality, that is the DEQ permitting process and responsibility.  However, the City and County are gaining knowledge through this Groundwater Investigation of the Billings Aquifer that there is the potential for water recharge and quality concerns over time. Understanding how this information may be used by DEQ, DNRC and the City and County may help in preventing significant challenges in the future if current and future development outside the City begins to need municipal water and sewer services to continue to be viable.

The presentation at this meeting is another progression toward completion of this study and actual model scenarios that may be run with all of the data complete and model tested. While the model scenarios are not ready for this presentation, this information will help the Planning Board see what work has been done, some of the details of the data collected, and how the model testing now will lead to the team sharing some scenarios late this spring.


 

City and County staff, developers, DEQ, DNRC, City and County elected officials, the Planning Board and the public are all interested parties in the findings of this study. Staff has been in contact with the Board of County Commissioners and also will be in contact with the Billings City Council to share this information and, likely of more interest to the governing bodies, the model scenarios later this year. At this time, staff wanted the Planning Board to be brought up to date on the progress of the study since it was last shared in 2023 and what may be expected later this spring. It is the intent of staff to schedule one or more meetings this spring to enable this Board, the Board of County Commissioners and the City Council to all hear a presentation and see some of the model scenarios.

There are no alternatives or action expected at this time. This is for the Board's information as this study progresses and is completed in 2025.

There are no fiscal effects at this time. It may be that the County and City will decide at a future time to fund some ongoing monitoring and update work for well and nitrate data to provide local information and updates in the future.

This is an ongoing issue of interest to the Planning Board given its review of development activity in the City and County.