Friday, April 6, 2012

HW-1 Dimock Private Well Marcellus Shale EPA Sampling January 2012


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


Well – HW-1

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

Anionic Surfactants – < 0.01 mg/L – the secondary drinking water standard for foaming agents is 0.5 mg/L.  (OK)

Ethane 0.350  mg/L  – No specific drinking water standard (OK)

Methane 12.0 mg/L  – No specific drinking water standard. (OK).
The well water is above the new action limit of 7 mg/L and methane gas mitigation measures should be employed.  These measures not only include venting the well, but also potentially modifying the well, installing treatment, or taking other action.  For more details, go to http://www.water-research.net/methanegas.htm

There are places in PA were baseline levels of methane gas are at or above 7 mg/L. In general, I would estimate that 1 to 3 % of private wells may have elevated levels of methane.  In addition to modifying the well, it would be advisable to conduct isotopic analysis.  Based on the ratio of methane to ethane, the ratio is 34.  This suggests the gas is  of thermogenic origin and isotopic analysis is critical.  No specific health concern – but action needed to properly vent gas and it may be necessary to modify the well and isotopic analysis recommended.
May be advisable to check the level of other gases, such as propane.

Methane/Ethane Ratio: 34  (Thermogenic)

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.

Chloride – 4.36 mg/L (OK) – drinking water standard is <  250 mg/L – this does not suggest any specific impact.

Sulfate – 5.49 mg/L (OK) – drinking water standard is <  250 mg/L – this does not suggest any specific impact.

Barium - 0.304 mg/L (Total) and 0.316 mg/L (D) – drinking water standard is <  2 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- 7.89 mg/L (Total) and 8.21 mg/L (D) – no specific drinking water standard drinking water standard is available.  (OK)

Magnesium- 3.64 mg/L (Total) and 3.76 mg/L (D) – no specific drinking water standard drinking water standard is available.  (OK)

Manganese– 0.0022 mg/L (Total) and  0.0019 mg/L (D) – Manganese is regulated as a secondary drinking water standard in Pennsylvania and the action limit is 0.05 mg/L.  (OK)

Sodium –18.1 mg/L (Total) and 19.1 mg/L (D) – – 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 0.655 mg/L (Total) and 0.694 mg/L (D)  – 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)

Total Dissolved Solids  < 16  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.  (Question – this value seems inaccurate or a typo – This should be redone.)

No major problems

1. Heterotrophic bacteria data is not provided.
2. Methane/Ethane Ratio could suggest the source of the methane is Thermogenic and the level of methane is above the action level of 7 mg/L.
Go to: http://www.water-research.net/methanegas.htm
3.Total Dissolved Solids results seem inaccurate or there is a typo in the draft report.
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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A Well by Well - Review of the Data for Dimock, PA collected by EPA


Free Information on Drinking Water Quality - http://www.water-research.net

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