Disclosure Notice: I am the chair of the Groundwater Advisory Committee (GWAC) of the Oregon Water Resources Department (OWRD). The GWAC is comprised of volunteers from the groundwater industry and advises the Water Resources Commission:
...on all matters relating to rules, legislation, and public policy for the development, securing, use and protection of ground water; licensing of well constructors, including the examination of such persons for license; and reviewing the proposed expenditures of all revenues generated under ORS 537.762(5).
I am in my sixth and final year on the GWAC.
Now to today's post.
As I noted on Friday's post I spent some time out in the Harney Basin (Burns, OR) last week working with local folks on water availability and related issues as part of a community-based water planning (CBWP) effort supported by the Oregon Water Resources Department, which, along with the USGS, is conducting a groundwater study in the basin. The Harney County Watershed Council received the grant and is coordinating the effort. I am volunteering to help them in any way that I can for as long as I can.
Below is a revised version of the PowerPoint (and PDF) I presented (c. 30MB) on 5 April at a meeting of the Water Availability Group of the CBWP. Great bunch of folks, engaged and informed.
If the Harney Basin rings a bell, it was mentioned in the recent series in the Oregonian, Draining Oregon. The basin is one of the places in eastern Oregon where a lot of irrigation water is pumped, yet no one knows, not even the OWRD or the USGS, exactly how much is pumped or how much recoverable groundwater exists. Not a good way to manage groundwater, or any similar resource. Groundwater levels are dropping but not all throughout the basin. In fact, the lithology and structure may be such that the basin is compartmentalized into sub-basins that do not have great hydraulic communication with one another.
At this point the interested reader might want to read my blog post on the Draining Oregon series.
Todd Jarvis was gracious enough to provide a link to Lauren Smitherman's thesis, Forensic Hydrogeography: Assessing groundwater Arsenic Concentrations and Testing Methods within the Harney Basin, Oregon, which contains useful geologic and other information. The abstract and graphics below are from her thesis.
Harney County contains defining characteristics of regions containing arsenic within the groundwater such as its location in the western United States, unique closed basin geography, complex geology, and seasonal groundwater level fluctuations. Confirmation of arsenic concentrations above the Maximum Contaminant Level Drinking Water Standard of 10 μg/L has been observed on a recurring basis. Private land owners within the Harney Basin solely depend on private wells for domestic, agricultural, and livestock water supply and are not required to test for or meet the 10 μg/L MCL water quality standards for public water systems, as established by the United States Environmental Protection Agency. The purpose of this study was to expand on previous arsenic investigations to determine if a relationship exists between arsenic occurrence and the geography, hydrology, and geology within the Harney Basin. The effects of well depth, latitude/longitude, and hydrogeologic units were analyzed to create a regional depiction of arsenic occurrence through a conceptual model. For each sample, total arsenic, pH, and conductivity was measured. A total of 140 samples were evaluated, 91 were integrated from previous studies and 49 were collected throughout the Harney Basin as part of this study. For each of the 49 samples collected in this study, total arsenic was quantified by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and semi-quantitative arsenic field screening tests were also performed for comparison. These data were used to determine if a link exists between groundwater arsenic occurrence, geology, and the source aquifer. The secondary purpose of this study was to assess the accuracy and precision of the field tests to inform the community if a more available and less-expensive option than ICP-MS could be used for routine monitoring. Data acquisition was challenging due to citizen concerns about anonymity, difficulty contacting land owners, and their perceived effects on land values. The analysis identified that arsenic contamination is widespread throughout the valley. While one hydrogeologic unit provided statistically higher concentrations of arsenic, there is no single clear geogenic source of arsenic. The results from the field test produced questionable results, with both overestimates and underestimates of concentrations compared with the ICP-MS analysis. The results of this research will be informative to groundwater users and public health officials and the results will be confidentially shared with stakeholders. Communities reliant on private well water with similar geologic characteristics may utilize this report to understand the importance of arsenic testing.
The folks in the basin depend upon irrigated agriculture and are understandably anxious about the OWRD-USGS study and what it might show. It's interesting to note that the OWRD is supporting CBWP but also conducting a study that could limit further groundwater development.
There has been some talk among the stakeholders about creating a groundwater management district. I find that idea intriguing and worth pursuing. It would be a first in Oregon.
Here are some materials provided by Harmony Burright, the OWRD planning liaison:
Background and updates on place-based planning: http://www.oregon.gov/OWRD/Pages/Place_Based_Planning.aspx
Background and updates on the groundwater study (including presentations and notes from advisory committee meetings): http://www.oregon.gov/owrd/Pages/Place/Malheur_Lake_Basin.aspx
Copy of the Groundwater Study Work Plan: http://www.oregon.gov/owrd/docs/Place/Malheur_Lake_Basin/USGS_OWRD_harney_groundwater_workplan_Dec2016.pdf
"To be absolutely certain about something, one must know everything or nothing about it." - Olin Miller (thanks to Bill and Rosemarie Alley, High and Dry, p. 68)