Laurie Morgan, Hydrogeologist

Transcription

1 Laurie Morgan, Hydrogeologist Washington State Dept. of Ecology Water Quality Program Presented to the GWPC October, 2014

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3 Columbia Basin 2001 Lower Yakima 2011 Chapter WAC Ground Water Management Areas and Programs Washington Ground Water Management Areas - Nitrate

4 3. Weiser

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6 Goals Delineate areas where nitrates are high in groundwater Prioritize those areas by impact to people and resources Make information available to everyone

7 Inputs Database of nitrate sampling results for groundwater from state and federal databases USGS nitrate risk studies GIS resources, such as soils, surficial geology, and irrigated areas Select topographically distinct areas at high risk of groundwater contamination by nitrate Prepare project information, data and GIS layers for a future web based map application

8 For consideration Now Delineate Nitrate Priority Areas Prioritize using criteria developed with partners (especially WDOH) Loading Estimate Method Hydrogeologic Facts on a Map Strategy for Tracking Conditions and Trends Web map deployment

9 Bellingham Seattle Spokane Tacoma Olympia Yakima Hanford Pasco Richland Kennewick Walla Walla Vancouver Urban Crop Lands Shellfish Beds Tribal Lands

10 Mt Baker Rocky Mountains Glacier Peak Olympic Mountains Mt Rainier Columbia Basin Willapa Hills Mt Saint Helens Portland Basin Mt Adams Mt Hood Volcano Blue Mountains

11 Source: WA Dept. of Natural Resources, Division of Geology & Earth Resources Quaternary Terrace Ringold Loess Dunes Alluvial Glacial Flood

12 Water Wells: 285,463 Resource Protection: 214,540 Abandoned Wells: 130,313

13 WA Dept. of Health: 16,327 well locations, 94,185 sample results, 2000 to 2011 USGS: 4,361 well locations, 9,215 sample results, 1970 to 2011 WA Dept. of Ecology: 2,963 well locations, 11,458 sample results, 1982 to 2012

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18 Historical Max >= 10 mg/l Nitrate as N Historical Max >= 5 & < 10 mg/l Nitrate as N Historical Max >= 3 & < 5 mg/l Nitrate as N Historical Max < 3 mg/l Nitrate as N

19 Historical Max >= 10 mg/l Nitrate as N Historical Max >= 5 & < 10 mg/l Nitrate as N Graphed Wells with Nitrate Graph 4 or more Samples, at least 1 >=5 mg/l Nitrate as N

20 Historical Max >= 10 mg/l Nitrate as N Historical Max >= 5 & < 10 mg/l Nitrate as N Graphed Wells with Nitrate Graph 4 or more Samples, at least 1 >=5 mg/l Nitrate as N

21 Grandview Historical Max >= 10 mg/l Nitrate as N Historical Max >= 5 & < 10 mg/l Nitrate as N Graphed Grandview Population ~ 11,000

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23 Grandview Mabton Blended Historical Max >= 10 mg/l Nitrate as N Historical Max >= 5 & < 10 mg/l Nitrate as N Graphed

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25 Wells with a Hyperlink USGS and Washington Dept. of Ecology

26 Wells with a Hyperlink USGS Well Information Page

27 Wells with a Hyperlink Ecology Well Information Page

28 Historical Max >= 10 mg/l Nitrate as N Historical Max >= 5 & < 10 mg/l Nitrate as N

29 Nitrate Probability Grid (Frans, 2008) Hanford Tribal Frans, L.M., 2008, Estimating the probability of elevated nitrate concentrations in ground water in Washington State: U.S. Geological Survey Scientific Investigations Report , 22 p. Online at Percent Probability of detecting elevated nitrate concentrations in groundwater* * >= 2 mg/l at 145 depth below land surface

30 >= 50% for W. Washington >= 70% for E. Washington Nitrate Probability Grid (Frans, 2008) Frans, L.M., 2008, Estimating the probability of elevated nitrate concentrations in ground water in Washington State: U.S. Geological Survey Scientific Investigations Report , 22 p. Online at

31 Nitrate Prediction Grid (Nolan, 2006) Nolan, Bernard and Hitt, K.J., Vulnerability of Shallow Groundwater And Drinking-Water Wells to Nitrate in the United States, in Environmental Science & Technology/Vol. 40, NO.24, pp Online at >= 10 mg/l >= 5 & < 10 mg/l

32 High N Application High Water Input Well-Drained Soils High effective porosity soil/ fractured rock Lack of attenuation processes As N loading at the land surface increases, nitrate concentration in shallow groundwater increases

33 Most of Washington is Well Drained Lands adjacent to Puget Sound are to a greater extent Moderately Well Drained SSURGO Soils Drainage Classes of Washington Hanford Tribal Very limited areas of poor drainage Noticeable areas of excessive drainage, where water passes quickly through the soil profile Excessively drained Somewhat excessively drained Well drained Moderately well drained Somewhat poorly drained Poorly drained Very poorly drained

34 Excessively Draining Soils of Washington Hanford Tribal Source: NRCS SSURGO Soil Data, Downloaded Background Imagery Bing Excessively Draining Somewhat Excessively Draining

35 Irrigated Agricultural Areas of Washington Hanford Tribal Source: Washington State Dept. of Agriculture, Perry Beale, Background Imagery Bing

36 Background Imagery Bing Washington Dairies

37 Royal City Mattawa >= 10 mg/l >= 5 & < 10 mg/l Nitrate Sampling Max 5 to 10 and >= 10 mg/l Frans Nitrate Probability Grid Delineation Example Royal Slope & Mattawa, Columbia Basin Green draft outline based on sections Review and make any changes Refine line work based on natural boundaries >= 10 mg/l >= 5 & < 10 mg/l Nolan Nitrate Prediction Grid

38 Use multiple lines of evidence Historical nitrate sampling data Risk grids Soil conditions Irrigation/precipitation Presence of loading source Hydrogeology/groundwater use Bin areas Highly likely Moderately likely Somewhat likely After first draft areas are delineated, inventory the areas and categorize

39 Inventory areas Quantify and Describe Total wells sampled, percents over MCL Percent area with high risk conditions (USGS) Percent area with high risk soil conditions (such as excessive drainage) Irrigation/precipitation Loading source areal estimates Prioritize areas Severity of contamination indicators Population affected Availability of clean water alternatives

40 Priority Rank = Likelihood + Impact

41 Database errors Typos, locational Generally really good, but you must watch out for the occasional error. This is best done when working on a specific area as opposed to the entire state (limited checks) Public Water Supply data Where the sample was taken at the source or not Before or after treating/blending When did treatment/blending start Was the well abandoned possibly due to nitrate contamination issues All nitrate result data Well depth and construction Project purpose at a specific nitrate source, or ambient? QA level Nitrate is not as sensitive at higher levels (must follow sampling and lab protocols, important to keep sample cold) The data is always historical some of it is relatively recent

42 Hydrogeology Groundwater Web Atlas Make hydrogeological information easy to access. Compile information from various sources. Fund projects Address needs that are well defined and based on physical reality on the ground. Prioritize according to impacts on people s drinking water. Things that matter Bingo! Things we can control

43 Photo: Lyn Topinka (USGS) - [1]