A SIPHON GAGE FOR MONITORING SURFACE‐WATER LEVELS¹

Abstract

A device that uses a siphon tube to establish a hydraulic connection between the bottom of an onshore standpipe and a point at the bottom of a water body was designed and tested for monitoring surface-water levels. Water is added to the standpipe to a level sufficient to drive a complete slug of water through the siphoning tube and to flush all air out of the system. The water levels in the standpipe and the water body equilibrate and provide a measurable static water surface in the standpipe. The siphon gage was designed to allow quick and accurate yearround measurements with minimal maintenance. Currently available devices for monitoring surface-water levels commonly involve time-consuming and costly installation and surveying, and the movement of reference points and the presence of ice cover in cold regions cause discontinuity and inaccuracy in the data collected. Installation and field testing of a siphon gage using 0.75-in-diameter polyethylene tubing at Ashumet Pond in Falmouth, Massachusetts, demonstrated that the siphon gage can provide long-term data with a field effort and accuracy equivalent to measurement of ground-water levels at an observation well.(KEY TERMS: surface water hydrology; instrumentation; water level monitoring; Cape Cod; wetland hydrology.)

Monitoring the Removal of Phosphate from Ground Water Discharging through a Pond‐Bottom Permeable Reactive Barrier

“…During installation of the PRB, the HMPS were assembled on the shore by coupling four 3.3‐m‐long prefabricated sections. The HMPS then were positioned so that they extended about 12‐m perpendicular to shore, with the shoreward‐most sampling ports set at the shoreline position at mean pond stage [13.5 m above sea level (NGVD29) based on records from a nearby pond‐stage siphon gauge (McCobb et al 1999)]. The deep HMPS of each pair was placed on the bottom of the excavated section (sampling ports facing downward), and untreated sediment was placed by hand on the PVC pipe.…”