Prototype Development Of Three Bi-Directional Autonomous Groundwater/Surface Water Seepage Meters

Three different bi-directional autonomous groundwater/surface water seepage meter prototypes were designed and developed from 2003 to 2006 under the collaboration of FDEP, FSU and SDI Environmental Services, Inc. All three seepage meters are self-contained automated systems including seepage collector, flow rate sensor, on-board controller, data logger, battery pack, and deployment/retrieval accessories. The first seepage meter design uses a Doppler flow rate sensor mounted on top of the seepage collector. The second seepage meter design uses a thermal flow rate sensor with detached seepage collectors. The latter design allows the use of multiple collectors to increase/decrease the measurement range of the meter. The three different meter sensors and collector combinations allow the measurement of seepage rates over a relatively wide range, with some overlap. The Doppler seepage meter has the highest measurement rate which is suitable for seashore and high seepage rate locations deployment. The two thermal seepage meters have low measurement rates which are suitable for lakes, rivers, and low seepage rate locations deployment. All three seepage meters were tested in the lab and field and proved to be easy to deploy and retrieve, and were dependable for long-term operation and monitoring of groundwater/surface water interactions.