The Lower Elkhorn Natural Resources District (LENRD) is accepting proposals or quotations for each of the study tasks associated with the following project:
The Nebraska Environmental Trust supported study: “Observing Water and Nutrient Mobility in the Vadose Zone”
Proposals must be submitted by June 19, 2026. The award will be granted no later than July 24, 2026.
Study tasks:
- Geodatabase development and study data management
- Geological, agronomic, and vadose zone field data collection, interpretation, analysis and consulting
- Nuclear Magnetic Resonance Imaging
- Direct-push sampling and hydraulic profiling
- Continuous vadose zone coring
- Groundwater monitoring well installation
- Laboratory analyses
**Click on the link to view the corresponding Request for Proposal/Quote
Prospective firms may approach this project in any manner they see fit, provided that all components of the requests for proposals being sought are met. For Project Task 7, firms may submit a quote to complete all requested analyses, or the water, soil, and other analyses separately. Consulting firms may form teaming arrangements, but every task-specific submission must come from and be administered by a single firm. Firms may submit a single proposal for multiple tasks at their discretion and should indicate any/all study task(s) in the subject line of their submission. Project Information, scope of work, and submission requirements are included in each request for proposal and are summarized below.
Project Background:
The Lower Elkhorn Natural Resources District (LENRD) promotes sustainable stewardship through conservation, resource management, and environmental protection. We protect lives by managing water resources, pollution control, and waste disposal for sustainable use and conservation, protect property through erosion control, flood management, and soil conservation, and protect the future by improving drainage, managing habitats, developing recreation facilities, and sustaining forests and rangelands. The LENRD’s “Observing Water and Nutrient Mobility in the Vadose Zone” study is supported by a generous grant from the Nebraska Environmental Trust (NET).
Project Objective:
The “Observing Water and Nutrient Mobility in the Vadose Zone” study seeks to build on historic observations by construction and utilization of a field-scale observation system that will help us evaluate nutrient and water mobility under conventional farming, limited tillage, and regenerative cropping systems in the context of local weather, soil, and hydrogeologic conditions. This will help LENRD and others understand which “best management practices” are better and adopt appropriate incentives to protect water quality or prevent contamination while maintaining or enhancing recharge to our aquifers.
Scope of Work:
The study seeks to gain access to eighteen fields under row-crop production at six to nine locations in the LENRD that will be observed during the 2027 and 2028 calendar years. The study completion report for the study is planned to be finalized in June of 2029. We will seek access to irrigated and dryland fields characterized by three different soil textures (sandy, silty, and clayey) and three different cropping systems (conventional, no-till/conservation tillage, and regenerative agriculture/continuous cover crop). LENRD will identify and recruit producers to allow access to these farms for the study duration and secure easements to install and maintain monitoring wells over the long term at selected sites as needed.
Each location will be instrumented with a means of recording precipitation, evapotranspiration, soil moisture content/temperature/electrical conductivity, and groundwater level on an hourly basis. Spot measurements at each location will include discrete depth soils samples within and below the crop root zone, and surface nuclear magnetic resonance (NMR) soundings, electrical resistance tomography (ERT) and induced polarization (IP) profiles that coincide in time and space with the soil samples, NMR, and/or tracer locations, and water quality samples from the monitoring wells prior to spring planting and during crop senescence to capture the pre-crop and post-crop conditions. Preplant and in-season fertilizer application timing and rates will be obtained for each field from the producers. In addition to spring and fall readings, staff will collect additional in-season water meter readings to better discretize groundwater pumping data from the irrigated systems.
One or two locations may be co-located with existing monitoring wells. In locations needing wells, we will drill test holes to collect continuous cores (vadose zone) and cuttings (aquifer strata) and geophysical boring logs to produce detailed geologic and geophysical descriptions of regolith and strata from the land surface to Cretaceous bedrock. At each test hole location, we will install monitoring well pairs with dedicated sampling hardware together with water and weather monitoring systems that will collect and transmit groundwater level, temperature, and weather data. Borehole NMR data will be collected to map water content, pore size, bound/mobile porosity, and Hydraulic Conductivity in the vadose zone. Also, we will collect soil samples from the vadose zone and create electrical conductivity (EC), injection pressure (HPT), and HPT flow profiles at each location with a direct-push rig (at 18 fields up to 50 feet below ground surface). In locations where monitoring wells already exist, weather stations will be added and vadose zones samples collected by direct-push technique during the spring and fall field excursions in 2027 and 2028.
In the second crop year (2028, at sites that exhibit divergent results), we will select up to 6 sites to incorporate a one-time bromide tracer to compare expected nutrient movement due to the physiochemical characteristics of the vadose zone. Subsequent vadose zone sampling for the tracer and nitrate concentrations will allow us to discern how much influence the vadose zone’s microbial community impacts nitrate fate and transport (e.g., denitrification, assimilation, etc.) under the field specific soil texture, vadose strata, and cropping system.
All data collected during the study will be shared among partners through design and deployment of an online database and mapping software that will result from the integration of data threads, database population, online implementation, and design of maps, applications, and 3-D scenes. Study partners whose deliverables include data will receive tech support to facilitate the formatting, upload and sharing of study data.