INVESTIGATION OF POTENTIAL FOR METHYL MERCURY PRODUCTION AND INPUTS FROM IRRIGATION DRAINS IN NEVADA

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0222933
• Project Start Date: Jul 1, 2010
• Project End Date: Jun 30, 2013
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF NEVADA
(N/A)
RENO,NV 89557

Performing Department
Natural Resources & Environmental Sciences

Non Technical Summary
Water is a limited yet necessary resource in the western United States. Agriculture and industry rely upon water delivery for day to day operations. Residential households in Nevada also require water. Wildlife populations are dependent upon water for nesting, resting and foraging activities. Water is a resource that connects all corners of society and impacts each level of the food chain. Activities such as mining and agriculture that brought many people to Nevada have impacted the state's watersheds. The passage of the Reclamation Act in 1902 brought many settlers to Nevada where the semi-arid climate necessitated the diversion of river water to cultivate land (NDEP). During the late 1800's through the early 1900's, tons of elemental mercury were released into local rivers during mining operations; in addition due to the inherent geology of Nevada many areas are mineralized and naturally enriched in mercury and these areas underlie irrigated landscapes or components of the irrigation system. In Nevada, most of the river systems terminate in reservoirs, lakes, sink areas, or wetland areas where contaminants may be concentrated. Many of these terminal areas are managed as wildlife areas where residents and visitors actively hunt, fish and engage in other recreational activities. According to 2006 data from the Nevada Department of Environmental Protection, fish consumption advisories due to mercury contamination were issued for 19 reaches of water bodies in the state. The proposed research study will evaluate the potential for delivery of mercury and methyl mercury from irrigation drainage ditches into receiving water bodies. The results will help managers determine the role, if any, irrigation drainage ditches play in conveying mercury into surface waters and the potential for these areas to be sites of conversion of inorganic mercury into the biologically harmful methyl mercury and what physical features, soil conditions, water chemistry, or biological communities encourage this transformation. Information developed on potential for methyl mercury production in agricultural drains will be put into fact sheets that may be distributed to farmers and ranchers across western states having irrigation drains that are impacted by Hg contamination. With population increasing in the west, agriculture and recreation could greatly impact the economies of rural areas in Nevada. By understanding the impact drainage from irrigation has on the water system, mitigation can be more effective resulting in fisheries, hunting grounds, and recreational areas that support healthy wildlife populations that are safe for human consumption. Water will continue to be a critical need and the more we understand water contamination problems the more tools we'll have to manage and promote healthy resources for people and wildlife.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
112	0320	2000	50%
133	0330	2000	50%

Knowledge Area
133 - Pollution Prevention and Mitigation; 112 - Watershed Protection and Management;

Subject Of Investigation
0320 - Watersheds; 0330 - Wetland and riparian systems;

Field Of Science
2000 - Chemistry;

Keywords

mercury

irrigation drain water

methyl mercury

Goals / Objectives
The goals of the study are to determine the potential for irrigation drainage ditches to act as sites for methyl mercury production and their significance as sources of methyl mercury to receiving water bodies. It is well known that wetlands are important sources of methyl mercury to flowing water systems and we hypothesize that irrigation drainage ditches in the arid west will be analogous to wetland systems.This will be evaluated through experimental mainpulations to assess drain conditions that may promote methyl mercury production and by collection of samples in three watersheds (Truckee, Carson and Walker) to assess potential methyl mercury inputs from current irrigation drains to the recieving water bodies. For the field reconnaisance study two areas per watershed will be selected. Samples will be collected in the receiving water body upstream and downstream of irrigation inputs and in drainage ditches four times over the course of each irrigation season over a two year period. Methyl and total Hg in filtered and unfiltered samples along with other water quality parameters (i. e. P, N, DOC, T, Conductivity, pH, Eh) will be determined. The controlled field experiments will be done at Main Station farm, Gund Ranch, at Rancho San Rafael and/or the McCarran Ranch flood control area (managed by the Nature Conservancy) to understand the conditions that would promote methyl mercury formation. Once information is developed a fact sheet will be developed as well as a regional stakeholder workshop would be convened. This project will be done in collaboration with UNCE, NDOW, USFWS, CABNR , Nature Conservancy and City of Reno flood.

Project Methods
Working with Kevin Piper at University Farm and Gund Ranch, Naomi Duerr and/or the Nature Conservancy-Patti Bakker (McCarran Ranch) and managers at Rancho San Rafael Park, we will develop field study plots where variables including soil Hg, water quality, vegetative cover, water flow rates, and other environmental conditions can be controlled. These sites will be used and manipulated to evaluate those factors most important in influencing methyl mercury production in irrigation drains. We will manipulate these plots with respect to vegetation, standing water, water quality (Truckee River water versus effluent at University Farm), environmental conditions, soil properties and mercury concentrations in soils. We will replicate plots where possible. Soil chemistry and water quality will be characterized with the parameters as investigated for the field reconnaissance study described below. . Within the Truckee, Carson, and Walker River watersheds, we will identify two areas impacted of significant irrigation drainage in each area. At sites under federal control, such as Stillwater National Wildlife Refuge and the Fallon National Wildlife Refuge, we will work with USGS and USFWS staff to identify these areas as well as upriver and downriver sampling locations. At sites under state control including the Mason Valley Wildlife Management Area we will work with Elmer Bull and his staff from the Nevada Department of Wildlife. Dr. Sue Donaldson with UNCE who is a water quality extension specialist and a Co-PI will help develop contacts and sampling access. From a minimum of two field reconnaissance sites within each watershed, water samples for filtered and unfiltered total and methyl mercury concentrations as well as a variety of water quality parameters will be collected within and in the receiving water body upstream and downstream of irrigation drainage systems four times during the irrigation season over two years. Where possible within the drain soil will be evaluated for Hg, methyl Hg, carbon, sulfate, iron, and physical properties. Water will be analyzed for Hg, methyl Hg, phosphate, nitrogen, sulfate, dissolved oxygen, conductivity, turbidity, temperature, and pH. Drain settings will be surveyed as best possible to characterize channels, vegetation, flow, sedimentation and surrounding landscape.

Progress 07/01/10 to 06/30/13

Outputs
Target Audience: The Nature Conservancy, US Fish and Wildlife Service, Nevada Division of Wildlife, Pyramid Lake Paiute Tribe, Lake Ditch Company and Truckee-Carson Irrigation District for site access and local support. Changes/Problems: We did not do a controlled field experiment.After considering where to do this nothing seemed logistically feasible. Plus it seemed more realistic to sample at real field locations. The collaborators ended up being The Nature Conservancy, US Fish and Wildlife Service, Nevada Division of Wildlife, Pyramid Lake Paiute Tribe, Lake Ditch Company and Truckee-Carson Irrigation District. We will not write a fact sheet for Susan Donaldson and Christianna Peterson were responsible for that task, and Sue is no longer with Nevada Cooperative Extension and Christianna Peterson did not finish this task. Additionally, Sue would have conducted the stakeholder workshop. What opportunities for training and professional development has the project provided? Five undergraduate students worked on this project. Two are co-authors on the manuscript submitted for Travis Lymanwas responsible for field sampling one year, and he and Musheng Alishahi were responsbile for analyzing most of the samples and processing most of the data. The other undergraduates that worked on this project included Lydia Peri, Vanessa Wehrkamp, and Larz Bolster. One graduate student Rebekka Fine actually wrote the initial proposal and worked on this project until we ended up with a specific dissertation topic that was good for her. How have the results been disseminated to communities of interest? Not yet. We will send them the manuscript once published. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Mercury (Hg) concentrations in water and sediments were monitored in irrigation drains seasonally for years 2011 and 2012, along with those in source and receiving waters above and below drain inputs, for the three primary watersheds in Nevada, USA. Five areas of study were identified in the three watersheds. These included two locations in the Truckee River watershed, two in the Carson River, and one site associated with the Walker River. The sites on the Truckee (T) and Carson (C) Rivers were upstream (identified as T1 (Lake Ditch) and C1 (River Fork Ranch)), and those downstream of Hg contamination (T2 (Nixon) and C2 (Stillwater). The study area on the Walker River was below a region of natural/anthropogenic Hg contamination and identified as W2 (Mason Valley). Areas were chosen based on the presence of agricultural activity, accessibility, and partner cooperation. The latter was necessary in order to coordinate sampling with irrigation activities. At all 5 locations, irrigation drains were sampled during or soon after the first flush of irrigation season, and when active to determine loading to rivers. At each sampling location water samples were collected for total and methyl mercury analyses along with phosphate, sulfur, nitrogen and dissolved organic carbon.At each location and during each visitin-situ water conditions (temperature, dissolved oxygen, conductivity; YSI Incorporated, Model 85), pH (OakTon pH11 Series), and flow rate (Rickly Hydrological Co, AA current meter) were recorded, while water and sediment samples were collected for later analyses.

Publications

• Type: Journal Articles Status: Submitted Year Published: 2014 Citation: Investigation of methyl mercury in irrigation drains and impacts on receiving waters. Peterson, C.*, Gustin, M. Sexauer*, Fine, R. *, Donaldson, S. �, Lyman T. *, Alishahi, M. *, Miller, M.B*. *Department of Natural Resources and Environmental Science, University of Nevada Reno, College of Agriculture, Biotechnology and Natural Resources, Reno, NV, USA. � University of Nevada Cooperative Extension, Reno, NV, USA. submitted to Journal of Environmental Management

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Data was collected over two irrigation seasons in the Walker, Carson and Truckee River Watersheds of Nevada. We are finishing one set of analyses that entailed measurement of methyl mercury in sediments. Data is currently being compiled into a manuscript for submission to the Journal of Environmental Management. As the paper is being written we will also write a fact sheet targeting those that manage irrigation in mercurycontaminated watersheds. PARTICIPANTS: Six undergraduate students, a graduate student and two research faculty have worked on this project. This project is a collaboration with Dr. Sue Donaldson in Nevada Cooperative Extension. Sue helped with coordination with Nevada Division of Wildlife, the Nature Conservancy, the Paiute Pyramid Lake Tribe and the National Wildlife Service for sampling that needed to be done at very specific times in the irrigation season. She will also help construct a fact sheet. TARGET AUDIENCES: The target audiences are those operating irrigation districts and water managers in Nevada and those in other areas with mercury contamination watersheds. This information will also be useful to those managing areas for wildlife habitat and conservation within the state of Nevada, and globally, that are important for migratory birds. In Nevada we have birds that move across the state on the Pacific Byway. PROJECT MODIFICATIONS: Not relevant to this project. PARTICIPANTS: Six undergraduate students, a graduate student and two research faculty have worked on this project. This project is a collaboration with Dr. Sue Donaldson in Nevada Cooperative Extension. We also collaborated with the Nevada Division of Wildlife, the Nature Conservancy, the Paiute Pyramid Lake Tribe, and the National Wildlife Service TARGET AUDIENCES: The target audiences are those operating irrigation districts and water managers in Nevada and those in other areas with mercury contamination watersheds. This information will also be useful to those managing areas for wildlife habitat and conservation within the state of Nevada, and globally, that are important for migratory birds. In Nevada we have birds that move across the state on the Pacific Byway. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The overall goal of this project is to determine characteristics of agricultural irrigation drains that promote formation of methyl mercury that may be input to receiving water bodies and to determine the scale of this issue for settings in Nevada. This information is important for many western states and around the world where anthropogenic and natural Hg enrichment of terrestrial landscapes has occurred.

Publications

• No publications reported this period

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Data has been collected three times over 6 total sites in the Walker, Carson and Truckee River Watersheds. Research is progressing on track as per the proposal. PARTICIPANTS: Four undergraduate students, a graduate student and two research faculty have worked on this project. This project is also a collaboration with Dr. Sue Donaldson in Nevada Cooperative Extension. Sue has been critical for coordination with Nevada Division of Wildlife, the Nature Conservancy, the Paiute Pyramid Lake Tribe and the National Wildlife Service for coordination of sampling that needs to be done at very specific times in the irrigation season. TARGET AUDIENCES: Irrigation districts and water managers in Nevada. Those managing areas for wildlife habitat and conservation within the state of Nevada and important for migratory birds that pass through Nevada on the Pacific Byway. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Data is being assessed and analyzed.

Publications

• No publications reported this period

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: During this year we have identified sampling locations for the field reconnaissance component of this project as well have begun to purchase materials needed for analysis that will be done for this project. In addition components of the laboratory systems that needed to be established for the analyses that will be done are being taken care of. Field sampling for this project needs to be done primarily in March through July and the timing for the funding approval did not allow us to collect relevant data last year. In preparation for this project we visited several field sites to consider our ability to develop controlled field experiments would work for this project. Based on these visits we decided to do the reconnaissance field sampling in a variety of locations over the next year-see where the data leads us and determine based on this whether collection of detailed field data in well delineated areas may be a better approach. Based on this we have chosen the following areas to collect field data this spring and early summer with pristine indicating not impacted areas and impacted areas being those affected by mercury contamination: Carson River-Nature Conservancy- River Fork Ranch (pristine) and National Wildlife Service Stillwater National Wildlife Area (impacted), Walker River -Nevada Division of Wildlife- Mason Valley Wildlife Management Area (impacted), and Truckee River- Last Chance Ditch (pristine) and Paiute Pyramid Lake Tribe Wadsworth area (impacted). Sue Donaldson, project Co-PI, is arranging site visits with agency partners so that we will have established sampling sites in all areas in February/March. Based on the site visits we will establish a sampling plan that will include -sampling locations and the number and types of samples to be collected in each area. We will collect field samples in March/April, June/July and possibly August. Field sample collection timing will depend on water available and irrigation season. During field samples soil samples will be collected within the irrigation drains as well as water within the drains associated with specific conditions. Soils will be evaluated for total mercury (Hg) and LOI initially. Water will be analyzed for Hg, methyl Hg, phosphate, nitrogen, sulfate, dissolved oxygen, conductivity, turbidity, temperature, and pH. Drain settings will be surveyed as best possible to characterize channels, vegetation, flow, sedimentation and surrounding landscape. PARTICIPANTS: Thus far Dr. Mae Gustin,Dr. Sue Donaldson, graduate students-Rebekka Fine and Claudia Pizzaro and technicians- Christianna Peterson and Matthieu Miller have been involved with overall planning and getting prepared for this project. The partners for this project include UNR, Nevada Cooperative Extension, Nevada Division of Wildlife, U. S. Fish and Wildlife Service, Paiute Pyramid Lake Tribe,and the Nature Conservancy. TARGET AUDIENCES: The target audiences include those managing water in Nevada as well as those involved in managing wildlife areas impacted by irrigation drainage and those irrigating that return drainage waters to flowing water bodies used by humans and wildlife. The local and regional community of hunters, fishers, boaters, farmers, landowners, and others will benefit from waterways managed in an ecologically sound fashion. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The overall goal of this project is to determine characteristics of agricultural irrigation drains that promote formation of methyl mercury that may be input to receiving water bodies and to determine the scale of this issue for settings in Nevada. This information is important for many western states where anthropogenic and natural Hg enrichment of terrestrial landscapes has occurred.

Publications

• No publications reported this period