Green Medicine New Jersey Well Testing

GMNJ Well Test – August 22, 2023

Further to our earlier communication on GMNJ Well Test Notification and the Township Planning Board’s resolution, this notice is to inform the public that GMNJ will be conducting their well test on August 22, 2023.

Please refer to a copy of the West Amwell Township Engineer’s August 11th letter to those residents that live within a 3,000 foot radius of the GMNJ site, along with a copy of the well test plan prepared by GMNJ’s hydrologist and approved by the Township’s hydrologist for the GMNJ control well and those properties within a 2,000 foot radius selected for testing by GMNJ along with the GMNJ control well.  The following provides a general description of the pumping test and the additional measures the Township is taking to ensure that we have enough data from neighboring wells around the GMNJ site.

The primary test sites were selected by the hydrologists, are generally the closest to the GMNJ site, and will have their water depth levels monitored for at least a week prior to the test and are equipped with transducers in their wells to record data as the pumping test is conducted over eight hours. Additional sites will be included on the test date, selected by the Township to be monitored with depth readings taken manually by sonic depth reading equipment.

GMNJ Pumping Test

Four properties (primary sites) were chosen to be included as part of the well testing by the Township Engineer (hydrologist), whose owners have consented to the well test at GMNJ’s expense.  In addition, the township has selected three additional properties (participating sites) to be monitored at our expense, also located within the 2,000 foot distance from the GMNJ test well.  Residents within the 3,000 foot radius of GMNJ may engage a well contractor to conduct a simultaneous test (simultaneous sites) at their own expense and should follow instructions included in the August 11th letter, a copy of which also appears on the WAT website. The Township’s Engineer can be reached at 908-200-2816, William.burr@colliersengineering.com.

Pumping tests are used to estimate hydraulic properties, determine the amount of water available, potential recharge rates, storage potential, maximum withdrawal acceptable, and any impacts on surrounding wells or neighboring water bodies.

A pumping test is a field experiment in which water is pumped out of a well over a period of time, at a controlled rate and water-level response (drawdown) is measured in one or more surrounding observation wells and in the pumped well (GMNJ Control Well) itself; response data from pumping tests are used to estimate the hydraulic properties of aquifers, evaluate well performance and identify aquifer boundaries. As pumping occurs, with pumped discharge water diverted away from the GMNJ Control Well pump area, groundwater levels decline (drawdown). When the GMNJ Control Well pump is turned off, groundwater levels recover. Drawdown is measured in the GMNJ Control Well, and also in surrounding primary site monitoring wells, throughout the test period.

It is now common practice to use pressure transducers with built-in dataloggers to record water level data during aquifer tests, as it fully automates data collection – especially when more frequent readings are required. The GMNJ Control Well and the four primary site test wells will have transducers installed to record data.

For the participating and simultaneous test wells, water level measurements will be made manually with a sonic drawdown meter that measures well water depth before, during and following stress being put on the GMNJ Control Well. Note that test wells cannot be used during the test period.

Prior to applying stress to the GMNJ test pump well, a manual depth to water measurement (with date and time) will be recorded from each participating and simultaneous site well using a sonic drawdown meter.

Water level measurements will then be taken periodically throughout, and at the end of the eight-hour test period for the GMNJ Control Well.

The sonic drawdown meter transmits a sound wave into the well or pipe and measures the time for the pulse to return after contacting the water. Readings are shown on a display screen and recorded on the meter. The sonic drawdown meter allows for programming of parameters like well diameter, offsets, temperature, etc. in order to capture accurate readings.

Simultaneous well site testing has to be coordinated through the Township Engineer’s office and involves engaging a well contractor to take measurements.  Anyone wanting to conduct a simultaneous test will need to follow instructions from the well contractor and any work will be at the individual resident’s own expense.  Well contractors will typically consider the condition of the well in making their decision on agreeing to provide related services.  Costs may vary by vendor.  For example, Stover’s Wells and Pumps, Flemington, has said they would make professionals available to assist with testing at $175/hour and the GMNJ test is expected to run for eight hours.

Take note: well test participants may not use water from their wells during the eight-hour test.

Test results will be posted on the Township’s website after the data are compiled and prepared for posting.