Methyl tert-Butyl Ether Occurrence and Related Factors in Public and Private Wells in Southeast New Hampshire
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- 作者：Joseph D. Ayotte ; Denise M. Argue ; and Frederick J. McGarry
- 刊名：Environmental Science & Technology
- 出版年：2005
- 出版时间：January 1, 2005
- 年：2005
- 卷：39
- 期：1
- 页码：9 - 16
- 全文大小：325K
- 年卷期：v.39,no.1(January 1, 2005)
- ISSN：1520-5851
文摘
The occurrence of methyl tert-butyl ether (MTBE) inwater from public wells in New Hampshire has increasedsteadily over the past several years. Using a laboratoryreporting level of 0.2 
g/L, 40% of samples from public wellsand 21% from private wells in southeast New Hampshirehave measurable concentrations of MTBE. The rate ofoccurrence of MTBE varied significantly for public wellsby establishment type; for example, 63% of public wells servingresidential properties have MTBE concentrations above0.2 g/L, whereas lower rates were found for schools (21%).MTBE concentrations correlate strongly with urbanfactors, such as population density. Surprisingly, MTBEwas correlated positively with well depth for public supplywells. Well depth is inversely related to yield in NewHampshire bedrock wells, which may mean that there isless opportunity for dilution of MTBE captured by deep wells.Another possibility is that the source(s) of water to low-yield wells may be dominated by leakage from potentiallycontaminated shallow groundwater through near-surface fractures or along the well casing. These wellsmay also have relatively large contributing areas (due tolow recharge at the bedrock surface) and therefore have agreater chance of intersecting MTBE sources. Thisfinding is significant because deep bedrock wells areoften considered to be less vulnerable to contaminationthan shallow wells, and in southeast New Hampshire, wellsare being drilled deeper in search of increased supply.
g/L, 40% of samples from public wellsand 21% from private wells in southeast New Hampshirehave measurable concentrations of MTBE. The rate ofoccurrence of MTBE varied significantly for public wellsby establishment type; for example, 63% of public wells servingresidential properties have MTBE concentrations above0.2 g/L, whereas lower rates were found for schools (21%).MTBE concentrations correlate strongly with urbanfactors, such as population density. Surprisingly, MTBEwas correlated positively with well depth for public supplywells. Well depth is inversely related to yield in NewHampshire bedrock wells, which may mean that there isless opportunity for dilution of MTBE captured by deep wells.Another possibility is that the source(s) of water to low-yield wells may be dominated by leakage from potentiallycontaminated shallow groundwater through near-surface fractures or along the well casing. These wellsmay also have relatively large contributing areas (due tolow recharge at the bedrock surface) and therefore have agreater chance of intersecting MTBE sources. Thisfinding is significant because deep bedrock wells areoften considered to be less vulnerable to contaminationthan shallow wells, and in southeast New Hampshire, wellsare being drilled deeper in search of increased supply.