Dimock HW-17 arsenic, barium, methane, uranium, thermogenic gasEPA Findings

Comment

1. Without predrilling data, it is not possible to comment on the cause for any water quality problems.

2. Where possible, I have noted situations where elevated levels of a water quality parameter exists in Pennsylvania.

3. If duplicate analysis provided, I attempted to use the highest reported value.

4. New Document - http://water.epa.gov/action/advisories/drinking/upload/dwstandards2011.pdf

5. This is not about cause and effect; it is about a review of the data.

6. A Well by Well - Review of the Data for Dimock, PA collected by EPA

Well – HW-17

With the exception of the following parameters, the remaining values were reported as NOT Detected (U)

Barium – 0.239 mg/L – the primary drinking water standard for barium is 2.0 mg/L –– this does not suggest any specific impact and barium is typically detectable in non-saline impacted water at a level of less than 1 mg/L. (OK)

Calcium- 33.1 mg/L (Total)– no specific drinking water standard drinking water standard is available.  (OK)

Chloride – 7.12 mg/L (OK) – drinking water standard is <  250 mg/L – this does not suggest any specific impact.

Copper – 0.0035 mg/L (OK)- the secondary drinking water standard is 1.0 mg/L and the primary drinking water standard is 1.3 mg/L. (OK)

Ethane –0.040 mg/L  – No specific drinking water standard (OK)

Methane – 3.3 mg/L  – No specific drinking water standard. (OK).

The well water is not above the new action limit of 7 mg/L, but the well should be fitted with a basic vented well cap, but the level of methane is at a level were passive venting is recommended.   For more details, go to http://www.water-research.net/methanegas.htm

The methane/ethane ratio is (2.0/ 0.011) – 82.5

Magnesium- 6.64 mg/L (Total)– no specific drinking water standard drinking water standard is available.  (OK)

Manganese– 0.040 mg/L (Total)– Manganese is regulated as a secondary drinking water standard in Pennsylvania and the action limit is 0.05 mg/L.  Therefore, the total manganese content does not exceed the secondary drinking water standard.   (OK)

Nickel - 0.0012 mg/L (Total) – no specific drinking water standard drinking water standard is available, but the EPA has suggest a MCL of 0.1 mg/L.   (OK)

http://www.epa.gov/ogwdw/pdfs/factsheets/ioc/tech/nickel.pdf

Nitrate+Nitrite- N – 0.707 mg/L, this is well below the EPA / PADEP drinking water limit of 10mg N/L for nitrate-N and would also be below the limit of 1.0 mg N/L for nitrite-N. (OK)

Sodium –12.1 (Total) – no specific drinking water standard drinking water standard is available, but the EPA has added it to the Candidate List to provide more analysis.  The EPA’s initial value of 20 mg/L has been clearly identified as not realistic.  When chloride (salt is sodium chloride) is present at a concentration of over 250 mg/L, the water can have an “off” taste. At 400+ mg/L chloride, the water will taste definitely salty. (Source- Dr. Brian Redmond, Professional Geologist). (OK)

Strontium – 0.835 mg/L (Total)  – no specific drinking water standard drinking water standard is available, but it is on the EPA Candidate List.  The EPA recommends that drinking water levels of nonradioactive strontium should not be more than 4 mg/L.  The report limit is consistent with background levels in Northeastern Pennsylvania.  If the background level was above 4 mg/L, it would be advisable to test for radiological parameters, especially alpha/beta.  (OK)

Sulfate – 10.4 mg/L (OK) – drinking water standard is <  250 mg/L – this does not suggest any specific impact.

Total Dissolved Solids  – 52 mg/L   – Total Dissolved Solids is regulated as a secondary drinking water standard by the PADEP in Pennsylvania and the action limit is 500 mg/L. 

Uranium – 0.0037 mg/L (Total) – Uranium is regulated as a primary drinking water standard by the EPA and PADEP in Pennsylvania and the action limit is 0.030 mg/L.  (OK)

Zinc  – 0.0065 mg/L (Total) – Zinc is regulated as a secondary drinking water standard by the PADEP in Pennsylvania and the action limit is 5.0 mg/L.  (OK)

Arsenic – 0.0027 mg/L (Total) – drinking water standard is <  0.010 mg/L – this does not suggest any specific impact and arsenic is a common problem in NEPA – about 6 % of private wells have arsenic above 0.010 mg/L.  It would be advisable to monitor the arsenic level of the well on an annual basis.

  

Ethylene glycol –  the reported value is < 10 mg/L – there is no standard, but the EPA has a guidance limit of < 7 mg/L.  Other states have lower and higher standards:

New Jersey 0.300 mg/L (300 ppb)

Arizona 5.5 mg/L (5500 ppb)

New Hampshire 7.0 mg/L (7000 ppb)

Florida, Massachusetts, and Minnesota14.0 mg/L (14,000 ppb)

Minnesota

At a minimum, I would recommend retesting for ethylene glycol other other glycol compounds using a method that is more sensitive or conducting some type of standard additions analysis.

1. No major problem.

2. Arsenic was detected, but not above a drinking water standard, but annual monitoring recommended.

3. Methane/Ethane Ratio could suggest the source of the methane is of thermogenic

origin and the level of methane is well below the action level of 7 mg/L, but at the action level of 2 mg/L were passive venting is recommended.

Go to: http://www.water-research.net/methanegas.htm

4. Retesting for glycols using a more sensitive technique is recommended.

Document can not be copied in whole or part without the expressed written permission of Mr. Brian Oram, B.F. Environmental Consultants Inc. http://www.bfenvironmental.com

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