Friday, March 23, 2012

Well – HW-12 Dimock 1/26/2012 A Review


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.  This is based on my professional experience and other published data.
3. Where appropriate I made recommendations.

Well – HW-12

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

Chloride – 3.64 mg/L (OK) – drinking water standard is <  250 mg/L – this does not suggest any specific impact.

Sulfate – 5.20 mg/L (OK) – drinking water standard is <  250 mg/L – this does not suggest any specific impact.

Arsenic – 0.006 mg/L (Total) and 0.0058 mg/L (D) – 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.

Barium - 0.707mg/L (Total) and 0.716 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)

Boron – 0.0538 mg/L (Total) and 0.0522 mg/L (D) – no specific drinking water standard drinking water standard is available. EPA appears to have a long-term health advisory of 2.0 mg/L, but other states have limits that range from 0.6 to 1 mg/L.   Minnesota is the state with the lowest standard of 0.600 mg/L.  Therefore, this does not appear to suggest any form of impact.  (OK)

Calcium- 28.5 mg/L (Total) and 28.1 mg/L (D) – no specific drinking water standard drinking water standard is available.  (OK)

Iron – 1.24 mg/L (Total) and < 0.1 mg/L (D) – Iron is regulated as a secondary drinking water standard in Pennsylvania and the action limit is 0.3 mg/L.  Therefore, the total iron content exceeds the secondary drinking water standard.  Since the total value exceeds the limit and not the dissolved, this suggests that the primary recommendation would be to install a water treatment system to filter the iron colloids or particles from the water.  The water probably has a reddish or brown appearance. Elevated level of iron is a common water quality problem in Northeastern Pennsylvania.  Action is Recommended, because of an aesthetic issue. 

Magnesium- 4.77 mg/L (Total) and 4.67 mg/L (D) – no specific drinking water standard drinking water standard is available.  (OK)

Manganese– 0.12 mg/L (Total) and 0.139 mg/L (D) – 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 exceeds the secondary drinking water standard.  Since the manganese is in a dissolved form, the water could become browner in color over time.  Because the water coming out of the well has dissolved manganese, the water treatment system would require either chemical oxidation or some type of ion exchange system. Elevated level of manganese is a common water quality problem in Northeastern Pennsylvania.  Action is Recommended, because of an aesthetic issue. 

Nickel - 0.0012 mg/L (Total) and 0.001 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)

Sodium – 19.3 mg/L (Total) and 19.3 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 0.629 mg/L (Total) and 0.618 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)

Uranium 0.0018 mg/L (Total) and 0.0016 mg/L (D)  – 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  0.0054  mg/L (Total) and < 0.002 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)

Ethane 2.00  mg/L  – No specific drinking water standard (OK)

Methane 52  mg/L  – No specific drinking water standard, but the level indicates supersaturated conditions.  This means the well pump is pulling in water that is not in equilibrium with the atmosphere.  The well 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 26.  Since a ratio of methane to ethane of over 1000 typically suggests a biogenic source and a value of under 100 suggests a thermogenic source, the available information would suggest a thermogenic source for the gas.  As a guide, it may be possible to use a ratio to suggest the source of the gas- “ if the ratio of methane to ethane is 25, the source is thermogenic, but if the ratio is over 2500, then it is biogenic" (Mr. Bob Pirkle, President of Microseeps, Inc.), but between 25 and 2500 this is where isotopic analysis is critical.  


No specific health concern, but a health risk associated with the potential for a flammable environment.  


Action needed to properly vent gas from the well, perhaps modifying the well, water treatment to reduce methane level in the water to < 7 mg/L or more,  and isotopic analysis recommended.

May be advisable to check the level of other gases, such as propane.

Total Dissolved Solids  67  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.  (OK)

Chloroethane – 0.0002 mg/L – there does not appear to be a drinking water standard and the primary route of entry into the body is inhalation.  Chloroethane can be smelled at a level of 0.02 mg/L in water.  “In groundwater, chloroethane changes slowly to ethanol and a chloride salt as a result of reaction with water and chloroethane can be formed through chlorination.”    There does not appear to be an aesthetic issue, but Additional Monitoring Would be Advisable.  No specific health concern, but monitoring recommended.

Methyl Chloride (Chloromethane)– 0.0006 mg/L – there does not appear to be a drinking water standard that is regulated by the EPA or PADEP.  It appears that water companies throughout the country have reported detection of chloromethane in the water. It appears the EPA has provided a recommended lifetime health based exposure risk non-cancer for chloromethane of 0.030 mg/L.  “ Most (99%) of the chloromethane in the environment comes from natural sources.” (OK)


Bromide – In freshwater, bromide is typically less than 0.05 mg/L. Therefore, it would be advisable to retest using a method with a lower detection limit. If an ozone-based water treatment system is proposed, it may be best to have the bromide level of less than 0.0063 mg/L to prevent the formation of bromates.    Additional Sampling at a lower detection limit – no health concern (OK).

Additional Comments
Lithium - was reported at < 200 ppb or 0.2 mg/L.  There are no current federal standards for lithium in drinking water. To protect human health, EPA estimated that a lithium concentration in a potable water supply should not exceed 700 μg/l or 0.7 mg/L.

Methane gas appears to have a thermogenic origin.

Other References
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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3 comments:

  1. Note - if the homeowner installs a treatment system for iron and manganese, it is likely that it will reduce the level of arsenic

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  2. From experience in the Catskill Formation it appears that the strontium (hundreds of parts per BILLION) may be elevated. I have seen detectable strontium in wells before but (from recollection) was in the single digit to 10's of parts per billion range.

    One source you should be aware of is the Ivy Park TCE/PCE contamination case. I was one of the project officers/geologists when at PADEP a few years back. The project included thousands of samples of various media by various agencies. Weston (PADEP HSCP contractor) Solutions designed a database that was compatible with most lab ESS procedures and updatable with excel. While this was a multi-source organic contamination problem (for the most part) there is considerable inorganic data considered background.

    The main point in mentioning this is the large database of residential wells that is well over 100 that has organic and inorganic sample results. The PADEP Special Projects or HSCP geologist can probably give you more current information on this if you believe it might help in more data.

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  3. I have seen strontium levels as high as 6 mg/L for a well that was directly impacted by saline water, 2 mg/L indirect impact from saline water, and otherwise it is normally less than about 0.1 mg/L. In Luzerne County - it appears to range from not detectable to over 1 mg/L. It appears to be higher in Susquehanna County. If I had to guess, I would suspect that the saline aquifer plays a more significant role in the groundwater flow system.

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