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Thorndike Pond
Conservation Association

2008 Water Report of Thorndike Pond
Jim Banghart VLAP sampler

The water samples taken in the pond in June, July and August were consistent with prior years.
Acidity is the major issue facing our lake.  Acidity is measured on a scale of 0-14, with 7 being the ideal neutral level, consistent with distilled water.  Numbers below 7 are considered acidic.  A pH between 6 and 7 is considered ideal for fish so a pH greater than 6 is considered satisfactory.  Most lakes in NH are on the acidic side of neutral because of the acid rain we receive and acid depositions in our granite bedrock, the state average being 6.6.  Thorndike Pond samples ranged between 5.96 and 6.35 and as a result we were considered to be slightly acidic by the state.  You can see we are more acidic than the state average.  There is little we can do about it.  In our case the tributaries are acidic and we have a very low Acid Neutralizing Capacity (ANC).
Acid Neutralizing Capability describes the ability of a solution to resist changes in pH by neutralizing the acidic inputs.  On this scale high scores are considered good.  The state average is 4.9 (mg/L).  Our samples varied between 1.5 and 2.2, classified as extremely vulnerable by the state.  Again there is nothing we can do about that.
All of the above is consistent with prior years.  The only measurement observed to be statistically different from prior years was water clarity.  For this we had a transparency of 4.2 meters, nearly 30% better than recent years and the best we have seen in over 15 years.  This is also considerably above the state average of 3.2 meters.