2016 Groundwater Week: Alphabetical Content Listing
Achieving Energy Savings and More with VFDs
Larry R. Stanley
Advances in Groundwater Science and Practice
William Alley, Ph.D.
ASR Generation: Generating Green Energy During ASR Injection
Kent Madison
I will share my experiences of being the first ASR agriculture well in the world "So I have been told" and the process from helping write the state legislation to allow ASR in Oregon State to developing the project and generating renewable energy in the process. I will share how ASR generation can be added to a well that has a line shaft turbine pump installed in the ASR injection well. How the use of a regen module can be added to a variable frequencry drive with very little cost and a fairly fast payback. How the benefits of using an ASR down hole control valve adds greater flexibility to an ASR project while maintaining the water quality needed for a successful project.
A Technology Platform to Harness Speed and Certainty in Groundwater Remediation
Dan Nunez
This presentation will focus on utilizing a technology platform based on combined remedial approaches to maximize speed and certainty to achieve groundwater remediation objectives. The platform has a dual function; it sorbs contaminants quickly, removing them from the mobile phase and provides a high surface area matrix favourable for microbial colonization and growth. Contaminant availability within a risk pathway is therefore reduced, while at the same time contaminant destruction is accelerated. A discussion regarding the use of conventional technologies like groundwater extraction, soil excavation and in situbioremediation will show how combined technologies can significantly improve remediation efficiency. Data from full-scale field applications with long-term performance monitoring (>18 months) on mixed plumes with chlorinated solvents and petroleum hydrocarbons will be highlighted.
The presentation will include a case study featuring a Midwest manufacturing facility, which utilized the liquid activated carbon solution coupled with a slow release electron donor to control migration of a TCA and TCE plume offsite. Long-term performance data (18 months) showing up to a 99% reduction in contaminant concentrations was observed and will be discussed.
In addition, two projects located in the Northwest will be discussed - one an active service station where several technologies had previously been utilized for the treatment of MTBE, BTEX, and TPH, but had also fallen short of remedial goals. The second site consisted of mixed plumes from both a former gas station and dry cleaners. The site was a few city blocks away from a redevelopment project for the same client and there was concern regarding off-site migration due to the operation of a pump and treat system. With groundwater contamination as the primary concern at both sites and time/cost-sensitive deadlines rapidly approaching, a fast and permanent remediation strategy was required. Performance data and the results will be outlined.
Availability of Groundwater Modeling Software and Applications at the U.S. Geological Survey
William L. Cunningham
The U.S. Geological Survey develops numerical groundwater modeling software and applies that software at a variety of scales to address Mission-related water resources issues across the Nation. All software is in the public domain and conveniently available at no cost on the Internet. Most model applications also are in the public domain and available from the investigator. This presentation will discuss the groundwater flow and transport modeling software available from the U.S. Geological Survey, and demonstrate a new online resource for groundwater modeling applications completed by the U.S. Geological Survey across the Nation.
Environmental Noise Impact Assessment and Mitigation for Water Well Drilling
Donald Behrens
Noise level impacts generated by water well drilling operations have become major issues of contention in both urban and rural areas with new noise regulations establishing allowable levels at various distances. Some regulations restrict water well drilling to daytime hours to eliminate night-time noise impacts while others prescribe allowable day-time and night-time drilling sound levels.
Typical sound levels of water well drilling equipment exceed 100 dBA and 110 dBC during normal operations. Noise surveys, including detail frequency spectra measurements of all equipment operating on the drill site, are required for accurate computer modeling of the predicted off-site noise level impacts. The utilization of a beamforming array for acoustical imagining surveying of the water well drilling noise sources allows for improved source noise level and frequency identification.
The establishment and documentation of the drill site’s ambient sound levels prior to the well drilling operations are required for the compliance verification and noise mitigation system design.
Computer noise prediction modeling meeting ISO 9613 Standards is utilized to evaluate off-site drilling noise impacts and to establish the noise mitigation systems requirements to meet regulatory compliance levels. For accurate noise impact modeling, the drill site and adjacent area’s topography, land cover, and structures are modeled the account for noise blocking, reflection and absorption at any given location.
With the development of site specific noise impact models, noise mitigation systems can be evaluated to determine the most cost effective system(s) required to meet regulatory compliance levels.
In designing temporary noise mitigation systems for water well drilling operations, many factors need to be considered, including the mitigation system design for low frequency noise. Other considerations include access and egress to the equipment for operator’s safety, maintaining line of sight for the operators, minimization of heat gain, and maintenance of air quality and worker noise exposure.
Groundwater Modeling Analyses to Inform Aquifer Management Decisions in the Southern Nebraska Panhandle
Thad Kuntz, PG
In the southern Nebraska Panhandle, a cooperative modeling effort has been developed called the Western Water Use Management Modeling between North Platte Natural Resources District (NRD), South Platte NRD, and initially the Nebraska Department of Natural Resources to create a robust modeling tool for water resource management decisions. The NRDs are local governmental entities responsible for regulating and managing ground water pumping over several counties. This modeling effort extends from the Wyoming-Nebraska border in the west to Ogallala, NE in the east and from Alliance, NE (in the middle of the Nebraska Panhandle) in the north to the Nebraska-Colorado border in the south. The primary surface water bodies within the model are the North Platte River, South Platte River, and Lodgepole Creek. The principal ground water system in the area is the High Plains Aquifer that locally consist of alluvial, Ogallala, and Arikaree aquifers. This modeling utilizes three partially integrated models that consist of a surface water operations model of the North Platte River system that provides estimated pumping, canal operations and recharge, and river operations; a regionalized soil water balance model to estimate crop consumptive use, ground water pumping, and recharge; and a ground water model to provide storage and movement of water through the alluvial and High Plains aquifers. These models are being utilized by the NRDs for day to day operations and regional to sub-regional management decisions. Recent analyses of the High Plains Aquifer have been conducted using several different pumping allocation and climate scenarios to provide future estimates of aquifer drawdown and saturated thickness. Ultimately, the results of these analyses are used to help educate and inform the public and to provide the NRD Boards with information to aid their aquifer management decisions in determining the next increment of ground water pumping allocations.
How to Obtain and Leverage Real-Time Data Access to Reduce Risk
Eric Paulk
Overview
Water level and water quality data can be difficult and costly to retrieve and analyze, especially when it requires a trip to the field to manually collect readings from the instrument. Additionally, the task of sorting, manipulating, and formatting the data once its collected can be extremely time-consuming. With this method, it’s likely that critical information isn’t gathered and analyzed until well after it would have been most useful. This workshop will be a live demonstration of how to utilize a data services platform in order to gain access to real-time data. Participants will learn ways to simplify the task of filtering data for important results, including rapidly narrowing data by location, parameter, user tags, or project. Participants will also learn how to use customizable alarm notifications to limit potential problems and minimize damages when issues do arise.
Learning Objectives
- Analyze and access your data in a timely manner to limit potential problems, and minimize damages when issues do arise.
- Identify ways to spend less time manipulating data into your desired format.
- Keep track of all your projects and instruments in a central location.
Initial Results of an Assessment of Private Well Risks and Vulnerabilities
Steven D. Wilson
An assessment tool to evaluate private well risk and vulnerability was developed as part of a national program of outreach and education to private well owners. The 8-page assessment allows a professional to determine how well construction, site conditions, land use, geology, and other factors might impact water quality and the risk of well contamination. During 2016 as many as 720 assessments are being completed in over 20 states. The data from these assessments is being evaluated to better understand how long standing private well issues affect the perception of risk. Well characteristics (proper construction, proper maintenance), well owner knowledge, use of treatment devices, sampling frequency, land use practices near the well, and understanding of best practices will all be described and presented. Conclusions drawn from this unique dataset will be discussed as well.
Modeling the Potential for MNA of a Uranium Plume at a Fractured Rock Site
Jason R. House, CG, PG
A pump and treat system to remove uranium-impacted groundwater has operated on the site for two years, reducing concentrations to less than or near action levels. An evaluation of potential uranium mobility after system shutdown was conducted using geochemical and contaminant transport modeling to evaluate MNA as a component of the long-term remedy at the site. Geochemical testing for a suite of parameters was conducted for wells upgradient, downgradient, and within the plume at a former manufacturing facility in the Mid-Atlantic region that used uranium in its operations. The suite of laboratory-tested parameters include alkalinity, phosphate, chloride, sulfate, iron (total, ferric, and ferrous), calcium, potassium, magnesium, manganese, sodium, and uranium. Measured field parameters include pH, temperature, conductivity, dissolved oxygen, oxidation-reduction potential, and turbidity. Field and analytical data were input into PHREEQC to evaluate the speciation of uranium in groundwater. Subsequent PHREEQC modeling then evaluated changes in speciation with plume movement, and with upgradient, groundwater flowing through the core of the plume. Results of PHREEQC modeling were applied to the construction and calibration of an MT3D model to evaluate long-term plume behavior, adequacy of the existing monitoring network, and potential time frames involved in plume migration. The modeling suggests that post-shutdown, the plume remains relative immobile, due to plume dependence on sorption. Sensitivity analyses indicate that drastic changes in groundwater chemistry would be the only probable reason for equilibrium to change at the site. Such changes are unlikely given the lack of use of groundwater for water supply or industrial purposes current site use and that monitored attenuation coupled with groundwater use restrictions over a limited area would be protective of human health and the environment. The groundwater monitoring network is generally adequate for monitoring changes in plume dynamics. Monitored natural attenuation is a potentially viable option for this site.
New Groundwater Insights and Practical Advantages of Monitoring Pumping with Wellntel Systems
Joseph Fillingham, Ph.D.
When studying groundwater, scientists and practitioners work hard to minimize the influence of pumping in their data in order to understand the resource in the purest way. However, as pressure from pumping on the resource increases, it is becoming more important to accurately account for groundwater pumping in any groundwater study. So when measuring in wells or regions where levels may be influenced by pumping activity, it is important to track well pumping events in addition to groundwater levels in order to see the complete groundwater picture. It is in these metadata, that researchers can better diagnose, analyze, or remove or evaluate human influences on groundwater and increase the utility of the study overall. Beyond the practical applications of monitoring pumping activity, calculating new metrics, such as pumping minutes at local, regional, and national scales leads to new insights about groundwater use and the water-energy nexus.
Pumping vs. Air-Lifting to Maintain Injection Well Efficiency
John D. Bonsangue, PG
The Orange County Water District operates one of the largest injection well fields in the world. In an effort to maintain high injection flow rates, various backwash methods have been employed. This discussion will focus on the challenges and benefits associated with backwashing injection wells using conventional pumping and air-lift pumping techniques.
Software for the Design of Optimal Multivariate Groundwater Quality Monitoring Networks on a GIS Environment
Jorge Aceves De Alba
The aim of the optimal design of groundwater monitoring networks is to obtain the maximum level of information for one or several variables (water level, physicochemical parameters, or pollutants) at minimum cost by discarding those wells that provide redundant information.
The objective of this research was to develop a software that uses a Geographic Information System (GIS) supported by a methodology that employs geostatistical tools and the static Kalman Filter to define optimal multivariate groundwater quality monitoring networks. Within the specialized literature, there are different approaches to define monitoring networks, those that include GIS usually require the application of geostatistical analyses. The adopted methodology employs the Kalman filter as the estimation method within the optimization procedure. Originally, the application of this methodology was carried out in a series of routines written in the Fortran programming language which complicates the implementation for a non-specialized user.
The software presented in this paper provides a single free-access tool that allows to facilitate the design of optimal monitoring networks with the capability of verifying final results on a friendly-user environment. It has also the capability to assign weights to each monitoring site based on the correlation and distribution of analyzed variables.
As a final result, the spatial location of the optimal set of monitoring wells is displayed along with the level of importance of each one according to the amount of information it provides in the estimation of the monitored variable(s).
The objective of this research was to develop a software that uses a Geographic Information System (GIS) supported by a methodology that employs geostatistical tools and the static Kalman Filter to define optimal multivariate groundwater quality monitoring networks. Within the specialized literature, there are different approaches to define monitoring networks, those that include GIS usually require the application of geostatistical analyses. The adopted methodology employs the Kalman filter as the estimation method within the optimization procedure. Originally, the application of this methodology was carried out in a series of routines written in the Fortran programming language which complicates the implementation for a non-specialized user.
The software presented in this paper provides a single free-access tool that allows to facilitate the design of optimal monitoring networks with the capability of verifying final results on a friendly-user environment. It has also the capability to assign weights to each monitoring site based on the correlation and distribution of analyzed variables.
As a final result, the spatial location of the optimal set of monitoring wells is displayed along with the level of importance of each one according to the amount of information it provides in the estimation of the monitored variable(s).
The Groundwater Visibility Initiative: Integrating Groundwater and Surface Water Management
William Alley, Ph.D.
For most of the public, groundwater is out of sight and out of mind. Groundwater, and the boundaries that define it as a water management unit, are physically invisible to humans. Our inability to readily see groundwater contributes to groundwater’s lack of visibility in many discussions of water policy, governance, and management.
In many parts of the world, the failure to manage groundwater in an integrated, sustainable way could have severe consequences. Depleted and/or contaminated water reserves contribute to regional conflicts and create public health hazards. Subsidence causes significant damage to critical infrastructure such as roads and levees. Entire economies, based on water dependent agriculture and industry, are at risk.
In April 2016, AWRA and NGWA convened 24 water experts from across the United States and Canada in a day-long Groundwater Visibility Initiative workshop in Denver, Colorado. This seminal event sought to discuss the best way to elevate groundwater’s status in the international discourse on water policy, governance, and management by crafting recommendations for action.
The attendees tackled an agenda consisting of provocative talks by recognized experts, panel discussions, and breakout sessions. They articulated ways to better integrate groundwater into integrated water resources management and incorporate it into policies for agriculture, energy, environment, land-use planning, and urban development. This presentation will summarize the workshop findings and recommendations.
The Missing Ingredient to Healthy Farming: Understanding Groundwater Supply
Nick Hayes, CTO
Farmers are masters at seeing conditions and trends to manage inputs and outputs. It is widely understood that if relevant data are available, the farmer will use it well. So, most modern farmers study a dashboard loaded with metrics including seed count, nutrients applied, gallons irrigated, and production output, among many other statistics. Missing on that dashboard: the condition of the groundwater source on which they, and their neighbors, depend. It’s high time that vital statistic be inserted. Near real time data about groundwater levels in wells can be fed to the farm’s information system, providing insights into available supply. When connected with data about pumping or irrigating, a farmer has the complete groundwater picture, and can manage related systems smartly.
Variable Density Flow: Are Equivalent Freshwater Heads Necessary or Misleading?
Klaus Udo Weyer, Ph.D., PG, PHG
Variable density flow of subsurface fluids as freshwater, brackish water and brines may occur in areas with salt layers, contamination and hydrocarbon reservoirs. There are a number of computer programs available (SUTRA and others) all purporting to be able to calculate adequate flow pattern for freshwater and saltwater. These programs make use of velocity potentials [energy/unit volume] to determine gradients for subsurface flow. The use of velocity potentials requires three basic assumptions: (1) the energy within the gravitational field relates to unit volumes, (2) underground fluids are incompressible, and (3) equivalent fresh water heads stand for the actual energy conditions in a flow field. Equivalent freshwater heads do, however, not correctly represent the energy conditions in flow fields in the subsurface and all underground fluids are compressible. The above assumptions are not necessary when flow calculations are based on force potentials [energy/unit mass]. As the mass is measured in kilograms and a mass of 1 kg is independent of pressure, density, and temperature of the fluid the actual heads measured in piezometers containing fluids of any density, compression, or temperature are the correct head values and can directly be used in flow calculations by programs based on force potentials. Thereby the use of equivalent fresh water heads is unnecessary and even misleading. When using force potentials buoyancy forces can occur in any direction in space and are integrated in the resultant calculation for, head and density dependent, piezometric forces driving variable density subsurface flow under heterogeneous, hydrodynamic conditions. Clear and simple diagrams will visualize the differences between the two approaches and the advantages of using mathematically and physically correct force potentials over only mathematically correct velocity potentials.
Well Asset Management: Not Just for Utility Water Supply
Stuart A. Smith, CGWP
For groundwater-source water facilities, large or small, including irrigation and municipal water supply, wells are a distinctive part of a total engineered system. Wells are in close contact with the nonengineered "wild" environment and encounter numerous formation changes over their depth, as well as water chemistry and microbiological changes. Also, well components have large surface areas.
Well deficiencies or failures can be hard to detect in a timely fashion. However, current or potential issues can be detected and tracked with available methods, permitting preventive maintenance actions and treatment.
A feature that wells and wellfield arrays have in common with other engineered systems is the benefit provided by good design, material choices, and expert construction. Thus, a total life-cycle asset management program for “wild” wells involves planning, design, baseline documentation of performance, environmental condition and performance tracking to establish trends and make decisions over time, and planning service events proactively based on that tracking.
This presentation will focus on these points:
- Some challenges that wells face
- Planning that optimizes life-cycle cost management
- Maintenance monitoring recommendations (more than water level and flow rate, but please do that, too)
- Integrating the “wild” wellfield into your total asset management program.
A final point is that such asset management of wells is as viable for small systems with one or two wells as it is for large municipal systems. The tasks and goals are the same, but can be managed under time and budget constraints. In fact, small systems, without financial buffers for major service or capital replacement events, need such a well maintenance program most of all.
Groundwater-source utilities are “well-advised” to implement such designed proactive programs, including training, as an alternative to delegating well service in a reactive way (when performance declines or components fail) to well service companies.
An Assessment Tool to Evaluate Private Well Vulnerabilities and Risk
Steven D. Wilson
Basic VFD Startup (AA)
Larry R. Stanley
Best Suggested Practices: Reducing Problematic Concentrations of Radium in Residential Water Well Systems
Kathryn J. Butcher, CMP
Best Suggested Practices: Well Development
Kathryn J. Butcher, CMP
Best Suggested Practices: Well Disinfection
Kathryn J. Butcher, CMP
Borehole Geophysics - Building Cross Sections (AA)
Bruce Manchon, PG
Borehole Geophysics - Gamma Ray (AA)
Bruce Manchon, PG
Borehole Geophysics - Resistivity (AA)
Bruce Manchon, PG
Borehole Geophysics - Spontaneous Potential (SP) Logs (AA)
Bruce Manchon, PG
Changes in the 2017 Federal Tax Laws: How You Should Plan
Brent Ardit, CPA
Enhancing Motor Protection
Bob Pelikan
How To (Geophysically) Log A Water Well (AA)
James J. LoCoco
Hydrofracking: Groundwater, Not Oil and Gas
Jeffrey Williams, MGWC, CVCLD
Innovative and Time-Saving Techniques for Conducting a Low-Flow Groundwater Sampling Event
Bill Mann
Large Capacity Well Efficiency: Food Production, Energy, and Supply Challenges: System Operation and Maintenance
Gary M. Gin, RG
Large Capacity Well Efficiency: Food Production, Energy, and Supply Challenges: Water Use Calculation
John Pitz, CPI
Large Capacity Well Efficiency: Food Production, Energy, and Supply Challenges: Well Design
Marvin F. Glotfelty, RG
Large Capacity Well Efficiency: Food Production, Energy, and Supply Challenges: Well Development
Marvin F. Glotfelty, RG
Legally Structuring Your Business Activities To Comply With New Electronic Logging Device Laws
Tony Verillo
Lost Circulation Materials and How They Work! (AA)
Mark Whittle
McEllhiney Lecture: Groundwater Contaminants and Treatment Technologies
Peter S. Cartwright, PE
McEllhiney Revisited: Annular Space Research and Chemical Rehabilitation of Wells
Tom Christopherson
Mitigating Naturally-Occurring and Human Induced Contaminants in Groundwater
Jeff Angermann, Ph.D.
Current Treatment Technologies: What Options Do We Have?
Peter S. Cartwright, PE
Geochemical Conditions Which Initiate the Natural and Anthropogenic Release of Metals and Selected Mitigation Measures
James A. Jacobs, PG, CHG, REA
Metals such as arsenic, chromium, copper, nickel, zinc and lead occur naturally in the environment, and naturally occurring changes or anthropocentric activities such as mining or development can create geochemical conditions which will initiate the release of toxic metals into surface or groundwater. The talk will focus on the natural conditions that allow the leaching of metals from selected pyrite-rich mountain rocks in the Andes of Peru which create acid rock drainage related to climate change and glacial melting. A comparison of geochemical conditions will be made with a water recycling project involving wastewater reinjection in a south Florida aquifer and the initial unintended consequences of geochemical changes in the subsurface. Mitigation measures to address the natural and anthropogenic release of metals will be discussed.
Nebraska Annular Space Research-Beyond the Grout Study
Tom Christopherson
In its third year, the Nebraska Annular Space Research project is designed to study if grout material can be retroactively inserted into the annular space of fully gravel packed well in hopes eliminating a preferential pathway for contaminates to reach the groundwater reservoir. The study has focused on irrigation wells constructed prior to 2014. Currently Nebraska has approximately 100,000 active irrigation wells that were constructed prior to 2014. The contaminates of concern are nitrates, selenium, arsenic, and uranium. The study is scheduled for 5 years of research. In year three we are seeing positive results in wells that have been modified with the targeted grout seals. Additional testing will be needed to verify the sustainability of such results.
Reducing the Influence of Arsenic and Nitrates on Groundwater: The City of Phoenix Experience
Gary M. Gin, RG
Elevated concentrations of arsenic are naturally occurring in the aquifers underneath Phoenix and surrounding cities. In the past, Phoenix has utilized arsenic treatment systems and blending stations to reduce arsenic concentrations. Recently, Phoenix has implanted an ASR well program and has successfully diluted arsenic concentrations down to acceptable EPA Drinking Water Standards. Phoenix is also piloting another ASR well to do the same for elevated nitrate concentrations in these aquifers. The hope and intent is that we can reduce nitrate concentrations and eliminate the wellhead treatment and blending options.
Two-stage Fixed-Bed Biotreatment: Unlocking Contaminated Groundwater Sources
Jess Brown, Ph.D., PE
Leveraging bacteria indigenous to local groundwater, two-stage fixed-bed biotreatment can efficiently remove multiple contaminants simultaneously (nitrate, perchlorate, hexavalent chromium, VOCs, and arsenic) without generating a concentrated waste stream. This presentation will cover process fundamentals, testing, design, and performance of pilot and full-scale two-stage, fixed-bed biotreatment systems.
NGWA Director Candidate School
Kevin McCray, CAE
NGWA Government Affairs: 2016 and the Year Ahead
Lauren Schapker
Preparing for the Field: What to Take (AA)
W. Richard Laton, Ph.D., P.G., CPG
Safe Practice in the Groundwater Industry: Electrical Safety and Electrocution
Roger E. Renner, MGWC
Safe Practice in the Groundwater Industry: Slips, Trips, and Falls
Roger E. Renner, MGWC
Seismoelectric Groundwater Exploration
Ervin Kraemer
Sizing the Right Pipe for a Job
Dan Featherstone
Soils, Irrigation, and Groundwater Management
Steve Evett
Agricultural Management Practices and Impacts on Groundwater
Tess Russo, Ph.D.
This presentation will cover field experiments and modeling projects used to measure agricultural impacts on groundwater quantity and quality. We will assess issues regarding nutrient loading, metal mobilization, and groundwater overdraft. Methods discussed will include numerical models of physical flow, and statistical and machine learning based models. We will finish the presentation by reviewing current areas of research and concern.
Estimates of annual loads of nitrogen contributed to streams by groundwater, landscape, and point sources
Paul Capel
In many areas across the country, elevated nitrogen concentration of discharging groundwater impacts the water quality of streams. To better understand sources of nitrogen to streams in the Chesapeake Bay watershed, catchment-scale nitrate concentrations in groundwater were estimated using a statistical model based on three factors: nitrate concentrations in small streams at base flow, land use, and subsurface geology. The groundwater nitrate concentration, combined with estimates of baseflow volume, were used to calculate the annual loads of nitrogen contributed by groundwater to each catchment. The groundwater nitrogen loads were combined with annual stream total nitrogen loads, derived from an existing watershed model, to apportion the total stream loads into groundwater, landscape, and point sources. The annual total nitrogen stream loads were apportioned to seven sources: point sources, sources from developed, agricultural and undeveloped landscapes, and groundwater sources from the three land uses classes. From a water quality management perspective, only the point-source and nonpoint-source landscape loads can be readily managed. Any effect of landscape management on nitrogen sources from groundwater will be delayed by the subsurface transit time. The apportionment of total stream nitrogen loads to various sources can help set realistic expectations for the effectiveness of management decisions. This overall approach can be replicated for other areas of the country, as long as there are sufficient observations of nitrogen concentrations in streams at baseflow.
Estimation of ET for Groundwater Models Using the ITRC-METRIC Process
Charles Burt, Ph.D., P.E., D.WRE
Actual evapotranspiration estimates across a field or irrigation project are quite different from evapotranspiration estimates that are developed for irrigation scheduling. Actual evapotranspiration is impacted by irrigation scheduling practices, irrigation system distribution uniformity, disease, nutrition non-uniformity and problems, and numerous other factors that lower the actual ET from potential, plus cause spatial variation throughout and between fields. The ITRC-METRIC Process using LandSAT imagery and customized software and quality control has been widely used to examine non-uniformity within fields and actual historical ET (water consumption). The actual ET value is essential for accurate groundwater modeling – which is a completely new concept for groundwater modelers and does not fit into their standard modeling programs.
Estimation of Evapotranspiration
Kendall DeJonge
Estimation of evapotranspiration (ET) in crops is important for the purposes of irrigation scheduling, water rights transfers, and yield prediction. This presentation uses the Limited Irrigation Research Farm in northern Colorado as a research-based example of how ET can be quantified. Main focus will be on FAO-56 standardized crop coefficient methods, but other methods will be discussed such as water balance, energy balance, lysimetry, and sap flow. Additional practical emphasis will cover the practical, legal, and physiological differences between applied water and consumed water (i.e., ET).
Soil Water Sensing for Water Management
Steve Evett
Agricultural water management tends to be reactive and relatively ineffective is the soil water content and distribution in the crop root zone are not well known in time and space. Currently, there are many soil water sensors and sensing systems available to help inform management. The major types of sensors available will be discussed in terms of their relative accuracy and usefulness for management. Sensor telemetry systems and decision support systems that rely on soil water sensing will also be discussed.