Laurie Morgan, Hydrogeologist

Washington State Dept. of Ecology

Water Quality Program Presented to the GWPC October, 2014

Laurie.Morgan@ecy.wa.gov

https://fortress.wa.gov/ecy/publications/SummaryPages/1410005.html

Washington Ground Water Management Areas - Nitrate

Columbia

Basin

2001

Lower

Yakima

2011

Chapter 173-100 WAC – Ground Water

Management Areas and Programs

3. Weiser

Goals

Delineate areas where nitrates are high in groundwater

Prioritize those areas by impact to people and

resources

Make information available to everyone

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

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

No

w

Fo

r c

on

sid

era

tio

n

Richland

Bellingham

Pasco

Tacoma

Olympia

Vancouver

Seattle Spokane

Yakima

Walla Walla

Kennewick

Hanford

Urban

Crop Lands

Shellfish Beds

Tribal Lands

Olympic

Mountains

Blue

Mountains

Portland

Basin

Willapa

Hills

Columbia

Basin

Rocky

Mountains

Volcano

Mt Baker

Glacier

Peak

Mt Rainier

Mt Adams

Mt Saint

Helens

Mt Hood

Quaternary Terrace

Ringold

Dunes

Alluvial

Loess Glacial

Flood

Source: WA Dept. of Natural Resources,

Division of Geology & Earth Resources

Water Wells: 285,463

Resource Protection: 214,540

Abandoned Wells: 130,313

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

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

Wells with Nitrate Graph – 4 or more Samples, at least 1 >=5 mg/L Nitrate as N

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

Historical Max >= 10 mg/L Nitrate as N

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

Graphed

85’

2005

Grandview – Population ~ 11,000

Grandview

Historical Max >= 10 mg/L Nitrate as N

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

Graphed

Grandview

Mabton

Blended

Historical Max >= 10 mg/L Nitrate as N

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

Graphed

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

Wells with a Hyperlink – USGS Well Information Page

Wells with a Hyperlink – Ecology Well Information Page

Historical Max >= 10 mg/L Nitrate as N

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

Nitrate Probability Grid (Frans, 2008)

100

50

0

Percent Probability of

detecting elevated nitrate

concentrations in

groundwater*

Hanford

Tribal

* >= 2 mg/L at 145’ depth

below land surface Frans, L.M., 2008, Estimating the probability of elevated nitrate concentrations

in ground water in Washington State: U.S. Geological Survey Scientific

Investigations Report 2008–5025, 22 p. Online at

http://pubs.usgs.gov/sir/2008/5025/

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 2008–5025, 22 p. Online at

http://pubs.usgs.gov/sir/2008/5025/

>= 50% for W. Washington

>= 70% for E. Washington

Nolan, Bernard and Hitt, K.J., 2006. Vulnerability of Shallow Groundwater And

Drinking-Water Wells to Nitrate in the United States, in Environmental Science

& Technology/Vol. 40, NO.24, pp. 7834-7840. Online at

http://water.usgs.gov/nawqa/nutrients/pubs/est_v40_no24/est_v40_no24.pdf

Nitrate Prediction Grid (Nolan, 2006)

>= 10 mg/L

>= 5 & < 10 mg/L

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”

Hanford

Tribal

Excessively drained Somewhat excessively drained Well drained Moderately well drained Somewhat poorly drained Poorly drained Very poorly drained

SSURGO Soils Drainage Classes of Washington Most of Washington is “Well Drained”

Lands adjacent to Puget Sound are to a greater extent “Moderately Well Drained”

Very limited areas of poor drainage

Noticeable areas of excessive drainage, where water passes quickly through the soil profile

Excessively Draining Soils of Washington

Source: NRCS SSURGO Soil Data, Downloaded 2013. Background Imagery Bing

Hanford

Tribal

Excessively Draining

Somewhat Excessively Draining

Irrigated Agricultural Areas of Washington

Source: Washington State Dept. of Agriculture, Perry Beale, 2013. Background Imagery Bing

Hanford

Tribal

Washington Dairies

Background Imagery Bing

Green draft outline based on

sections

Review and make any changes

Refine line work based on

natural boundaries

Frans Nitrate

Probability Grid

Nolan Nitrate

Prediction Grid

Delineation Example – Royal Slope &

Mattawa, Columbia Basin

Mattawa

Nitrate Sampling Max 5 to

10 and >= 10 mg/L

50

55

60

65

70

75

80

85

90

95

100

Royal City

>= 10 mg/L >= 5 & < 10 mg/L

>= 10 mg/L >= 5 & < 10 mg/L

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

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

Priority

Rank = Likelihood + Impact

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

Things that

matter

Things we can

control Bingo!

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.

Photo: Lyn Topinka (USGS) - http://vulcan.wr.usgs.gov/Imgs/Jpg/Rainier/Images/Rainier84_mount_rainier_and_tacoma_08-20-84.jpg [1]