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HomeMy WebLinkAboutDDW-2024-009307July 1, 2024 Andrew Beecher Cinnamon Creek Rec Area 50 E North Temple St, RM 1205 Natural Resource Services Salt Lake City, UT 84150 Subject:MPA Result Notification, Spring #2 Upper (WS002); Cinnamon Creek Rest Area, System #03105, File #13495 Dear Andrew Beecher: The Division of Drinking Water (Division) suspects Spring #2 (Upper) (identified as WS002 in the Division’s database) to be under the direct influence of surface water (UDI) based on E. coli positive samples taken at the source. An initial Microscopic Particulate Analysis (MPA) sample was collected from Spring #2 Upper (WS002) on September 19, 2023 and scored 10, indicating a moderate risk for being UDI. A follow-up MPA sample was collected on June 3, 2024 and scored 0, indicating a low risk for being UDI. Therefore,an additional follow-up sample needs to be collected during high surface-water runoff conditions in 2025 to determine whether Spring #2 Upper is UDI. Please work with the Division to make arrangements for the second follow-up MPA sample in the spring of 2025. Please note that: ●The Division protocol requires two consecutive low-risk MPA samples for this source to be considered not UDI. ●This source will be classified as UDI if the result of the follow-up MPA sample in 2025 indicates moderate or high risk. The Division can re-evaluate this source at any time if there are circumstances that affect its susceptibility to surface water influence. For information about UDI and MPA sampling, see the attached UDI Definition and Possible Causes. 195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144830 • Salt Lake City, UT 84114-4830 Telephone (801) 536-4200 • Fax (801-536-4211 • T.D.D. (801) 536-4414 www.deq.utah.gov Printed on 100% recycled paper Andrew Beecher Page 2 of 3 July 1,2024 If you have any questions regarding this letter,please contact Sarah Page at (385)272-5778 or Brian Pattee at (385) 270-7272. Sincerely, Mark Berger Monitoring and Standards Section Manager Enclosure(s):Laboratory Report of MPA Sample Taken on September 19,2023 Laboratory Report of MPA Sample Taken on June 3,2024 cc:Ben Harker,Bear River Health Department,bharker@brhd.org Cameron Draney,P.E.,Division of Drinking Water,cdraney@utah.gov Jake Moss,System Operator,jake@heavydutyutah.com Andrew Beecher,Cinnamon Creek Rec Area,andrew.beecher@churchofjesuschrist.org Division of Drinking Water VSA Team,EQDWVSA@utah.gov UDI Definition and Possible Causes A groundwater source that is Under the Direct Influence of surface water (UDI)is vulnerable to contamination by pathogens found in surface water.This vulnerability could be because the sub-surface formation is not sufficiently filtering water as the water percolates through the formation or because the groundwater collection infrastructure is poorly constructed and allows surface water to directly contaminate the groundwater.The Division of Drinking Water ’s protocol determines and classifies a groundwater source as UDI based on one or more of the following factors: 1.Physical evidence of source deficiencies that allow,or have the potential to allow,surface water contamination of the source 2.MPA sampling results indicating surface water influence: a.One high-risk MPA sample result b.Two consecutive moderate-risk MPA sample results c.Inconclusive MPA sample results,such as alternating low-risk and moderate-risk results,along with other water quality data or observations of the source that indicate potential contamination by surface water 3.Water quality data indicating contamination by surface water,for example,Escherichia coli positive source sample results not caused by physical deficiencies,detection of Cryptosporidium or Giardia in the source water,etc. An MPA test (Item #2)consists of running the source water through a spiral-wound filter for a period of time.Particles collected by the filter are extracted in a laboratory,examined under a microscope,and identified.Particles that are expected to be found only above ground or in surface water indicate a risk of surface water contamination.Such indicators include chlorophyll-bearing algae,parts of flying insects,plant debris,Cryptosporidium,Giardia lamblia,etc.Some of these indicators are not pathogens,but their presence in the source water means the source water is susceptible to contamination by pathogens found in surface water. An MPA sample is rated as having a low,moderate,or high risk of UDI if the score is 0-9,10–19, or 20 and above,respectively.When basing the classification of a groundwater source on MPA results,the Division protocol classifies a source as UDI if any MPA sample is high risk or if any two MPA samples are moderate risk or above. The path that surface water takes as it flows to a groundwater source can and usually does vary with season and hydrogeological conditions.It is common for the flow path to be directly influenced by surface water under some conditions,such as during a high surface runoff during spring,but not to be directly influenced under others.So a surface-water-influenced water source may have MPA sample results of various risk levels,depending on the timing of the sampling.A true groundwater source that is not under the direct influence of surface water will always have only low-risk MPA results.