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Hangman (Latah) Creek Hydrogeologic Assessment, Focusing on the Latah Creek Wastewater Treatment Plant

Publication number Date Published
20-03-013November 2020
VIEW NOW Hangman (Latah) Creek Hydrogeologic Assessment, Focusing on the Latah Creek Wastewater Treatment Plant (Number of pages: 84) (Publication Size: 3228KB)

Microsoft Excel format (Publication Size: 29KB)
Note: TABLE A.2

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Author(s) Redding, M.
Description Hangman Creek (aka. Latah Creek) is a tributary to the Spokane River. There are concerns about nitrogen and phosphorous contributions from groundwater impacting surface water. The Department of Ecology conducted water quality sampling near the Latah Creek Wastewater Treatment Plant (WWTP) to determine if contaminants were present in groundwater and impacting Hangman Creek.

Samples were collected on three dates (Aug 2010, July 2012, Sept 2012) during the summer low-flow season. These samples were analyzed for nitrate, ammonia, orthophosphate, total dissolved phosphorous, and other indicator parameters. This study found many of these contaminants in groundwater but determined they were not causing increases in surface water concentrations. Analysis of indicator parameters supports that groundwater is not impacting surface water near the WWTP. Hangman Creek was determined to be a gaining reach at all sampling sites during each of the three sampling dates.

Table A.2 in Appendix A is linked to this report above, as "Microsoft Excel format."
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Contact Melanie Redding at 360-407-6764 or
Keywords Hangman Creek, nutrients, groundwater monitoring, nitrogen, phosphorus, groundwater, Latah
WEB PAGE Hangman Creek multi-parameter TMDL
WATERSHED Water Resource Inventory Area 56 Hangman
DATA Environmental Information Management (EIM) #MRED0002


Quality Assurance Project Plan: Hangman Hills Sewage Treatment Plant Nutrient Loading and Groundwater Study

Quality Assurance Project Plan: Sumas-Blaine Surficial Aquifer Long-Term Ambient Groundwater Monitoring