Water Works 18 - 3/29/03

Inadequate Analysis of Well Test Response Data

( Excerpts from Fellow Correspondent’s letter, continued. )

The first paragraph of this section (i) states that 5 wells did not experience drawdown that could be clearly attributed to pumping QVF-3:

(1) The Mathews well, located to the far north in Quakertown. Figure D-13 (attached) presents the data from this well. The vertical scale of the graph compresses all water level fluctuations to the point that interpretation is not possible. This well does appear to draw down when a straight edge is applied to the line. The plot’s vertical scale is completely inappropriate for the data.

(2) The Stothoff well, located far to the north of GSG and west of Quakertown. This well is plotted on Figure D-14. Again the vertical scale is completely inappropriate and data interpretation is impossible. This well is located near a pond that many residents have stated responds to influences other than rainfall. The response is correlated to seasonal water demands.

(3) The Fischera well, located north and east from the well QVF-3. Again the vertical scale is completely inappropriate and data interpretation is impossible. Using a ruler, some water level declines appear to be occurring after the transducer data ends. Due to the distance of the well and the up-dip location of the well, effects would be expected to occur in this well late in the test.

(4) The Lot 24 well, located west of the test well. There are only three data points which might show a downward trend. As with the other wells, the vertical scale is completely inappropriate and data interpretation is impossible.

(5) The Demicco well, located south of the test well. The test data indicates a decline and recovery of the water level after the pressure transducer had been moved to another well. A late response in the well should be expected. The well would not decline until the head in a deeper zone of the aquifer tapped by QVF-2 had been lowered. Again, the vertical scale compresses the data and makes interpretation of the data impossible.

In summary, there appears to be a much wider well response than presented in the report supporting the GSG/QVF application. However, the data presentation in the NJGS report makes this difficult to interpret. The data should be re-plotted and presented to the public on a reasonably scaled graph before proceeding with this permit application.