HW-14 EPA Dimock Data Review January 2012 Biogenic Gas

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.

Well – HW-14

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

Anionic Surfactants – 0.03 mg/L – the secondary drinking water standard for foaming agents is 0.5 mg/L.  (OK)

http://www.chemetrics.com/products/pdf/detergents.pdf

Ethane –0.0029  mg/L  – No specific drinking water standard (OK)

Methane – 3.8 mg/L  – No specific drinking water standard. (OK).

Methane/Ethane Ratio:131  (biogenic)

Note: Methane at the sink, possibly after treatment – 0.049 mg/L.

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

Sulfate – 14.40 mg/L (OK) – drinking water standard is <  250 mg/L – this does not suggest any specific impact.

Arsenic – < 0.001mg/L (Total) and < 0.001 mg/L (D) – drinking water standard is <  0.010 mg/L – OK

Barium - 0.0893 mg/L (Total) and 0.0857mg/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- 29.9 mg/L (Total) and 29.7 mg/L (D) – no specific drinking water standard drinking water standard is available.  (OK)

Copper – 0.0021 mg/L (Total) and < 0.002 mg/L (D)- Copper is regulated as a primary standard (EPA and PA) and secondary drinking water standard in Pennsylvania.  Primary standard 1.3 mg/L and secondary standard 1.0 mg/L.   (OK)

Note- the copper appears to be higher at the kitchen sink – this could suggest some type of chemical / biological corrosion within the distribution system.

Lead – 0.001 mg/L (Total) and < 0.001 mg/L (D)- Lead is regulated as a primary standard (EPA and PA) at 0.015 mg/L, but the action level in PA for source water is 0.005 mg/L.   The level of lead after the treatment system and distribution system is 0.0015 mg/L.

Note- the lead is higher at the kitchen sink – this could suggest some type of chemical / biological corrosion within the distribution system.

Magnesium- 5.27 mg/L (Total) and 5.28 mg/L (D) – no specific drinking water standard drinking water standard is available.  (OK)

Manganese– 0.0083 mg/L (Total) and  0.0078 mg/L (D) – Manganese is regulated as a secondary drinking water standard in Pennsylvania and the action limit is 0.05 mg/L.  (OK)

Nickel - 0.0016 mg/L (Total) and 0.0016 mg/L (D) – – 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

Sodium –9.42 mg/L (Total) and 9.26 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)

Zinc  – 0.0036  mg/L (Total) and 0.005 mg/L (D)  – Zinc is regulated as a secondary drinking water standard by the PADEP in Pennsylvania and the action limit is 5.0 mg/L.  (OK)

Note: After treatment the Zinc content is 0.0268 mg/L – this would suggest some form of chemical or biological corrosion within the distribution system.

Total Dissolved Solids  – < 10  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.)

Nitrate+Nitrite – 1.48 mg N/L, the EPA drinking water for nitrate-N/L is 10, but the primary drinking water standard for nitrate is 1 nitrite-N/L.  It is probably be ok, but it may be advisable to test for nitrite-N.  (OK)

No major problems

1. Heterotrophic bacteria data is not provided.

2. Methane/Ethane Ratio could suggest the source of the methane is biogenic.

3.Total Dissolved Solids results seem inaccurate or there is a typo in the draft report.

4. Higher levels for select metals suggest there could be some corrosion within the distribution system, but the levels do not exceed a primary or secondary drinking water standard.

5. Nitrate-Nitrite at 1.48 mg/L – it may be advisable to check the level of nitrite in the water.

6. 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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