Ethanol Production Plant Monitors Impacts to Water Supply and Stays in Compliance
Under current ethanol plant configurations, water use for ethanol production ranges from 4.0 to 6.8 gallons of water required per gallon of ethanol produced. With the average new plant producing 120 million gallons of ethanol per year, water yields in excess of 1,000 gallons per minute are required; therefore adequate water supply is essential to the operation of an ethanol production facility. Most ethanol plants in the United States use aquifer systems for their water supply (see Figure 1), and an in-depth aquifer analysis must be completed before a plant can be constructed or expanded. Some states require 60-day aquifer yield tests, and plants must continue to monitor impacts to groundwater resources during the life of plant operation.
Figure 1: A typical ethanol production plant in West Burlington, Iowa (Big River Resources, LLC). Photo courtesy of Steven Vaughn and the U.S. Department of Agricultur
Integrated solutions enhance data collection and analysis
Summit Envirosolutions, Inc. is a full-service environmental engineering and consulting firm that specializes in environmental site assessments and characterizations. To help environmental professionals use data more efficiently and to better understand project site dynamics. Summit Envirosolutions has developed proprietary Environmental Management Information Systems, including RealFlow* software. To develop an aquifer monitoring system that would help an ethanol plant stay in compliance. Summit Envirosolutions, Inc. worked with In-Situ* Inc. and delivered a total monitoring solution to the ethanol plant.
Previously, Summit Envirosolutions had worked with In-Situ Inc. to develop a customer-specific solution that used Level TROLL' 700 instruments to record groundwater elevations. However, site visits were necessary to download data, and with over 15 wells for an average aquifer test at a proposed ethanol plant, the mobilization and field effort was substantial.
To streamline the field effort and to take advantage of their data processing tools, Summit Envirosolutions used their RealFlow data analysis software with several In-Situ Inc instruments. A system of Level TROLL 700 (30 and 100 PSIG) and BaroTROLL* instruments connected to TROLL' Link 100 telemetry systems (see Figure 2) were installed in monitoring wells at an ethanol plant in Minnesota. The instruments were initially used to remotely collect data during a 30-day aquifer pumping test.
By using gauged Level TROLL* 700 instruments in conjunction with BaroTROLL instruments, ethanol plant technicians can precisely monitor water levels in the aquifer. The combination of instruments allows for evaluation and compensation of water level changes in the borehole that result from changes in barometric pressure. Once these changes are factored out, more subtle changes to aquifer water levels can be analyzed and monitored (see Figure 3).
Once collected, data is uploaded from the field into RealFlow software (see Figure 4) using the TROLL' Link 100 telemetry system. RealFlow software converts data from CSV file format to a Microsoft* Access* database. The software organizes and stores the data in a format that can be easily queried by location, parameter, and date. Hydrographs can be compared to other environmental parameters such as barometric pressure, precipitation, and river stage. The data can be exported to ArcGIS and other hydrogeologic analysis software.
The RealFlow software allows the user to view real-time and historic hydrogeological conditions of the instrumented well field, including well efficiencies, capture zones, specific capacity, and groundwater elevation contours generated using linear log kriging algorithms (see Figures 5 and 6).
Summit Envirosolutions believes that the TROLL Link 100 telemetry systems offer a simple, superior solution for remote monitoring, and the Win-Situ' Plus software is by far the easiest and most robust in the industry.
Staying In compliance with real-time, remote data access
Ethanol production requires a reliable water supply. Most ethanol plants are located where surface water supplies are not adequate and rely on groundwater supplies. Due to the regulatory requirements of aquifer impact analysis, combined with the rural location of ethanol plants, groundwater data collection and analysis can be costly with regards to travel expenses, data management, labor, and reporting costs. The use of In-Situ Inc and Summit Envirosolutions hardware and software systems provide the client with remote access, real-time data, and results that keep them in compliance with their state regulatory agency.
The total cost of remote data acquisition and automated data analysis provided the client with over 50 percent savings on hydrogeological services. In addition, real-time monitoring helps the plant stay in compliance and keeps groundwater pumps operating at optimal efficiency. By managing the drawdown and reducing the lift required to pump water, the plant will save over $20,000 annually in electrical costs.