Publication Summary

This document is one in a series describing the results of groundwater and surface water monitoring at the American Crossarm and Conduit (ACC) site. During 1998, samples were collected on May 5 and October 14 from four downgradient monitoring wells (MW-22, MW-23, MW-24, and MW-25) and two on-site surface water stations (ACCSW1 and ACCSW2). Prior to the October sampling, well MW-23 was damaged and subsequently has been decommissioned. All samples collected for this project were analyzed for polynuclear aromatic hydrocarbons (PAHs) and chlorinated phenolics.

This document is one in a series describing the results of groundwater and surface water monitoring at the American Crossarm and Conduit (ACC) site. During 1998, samples were collected on May 5 and October 14 from four downgradient monitoring wells (MW-22, MW-23, MW-24, and MW-25) and two on-site surface water stations (ACCSW1 and ACCSW2). Prior to the October sampling, well MW-23 was damaged and subsequently has been decommissioned. All samples collected for this project were analyzed for polynuclear aromatic hydrocarbons (PAHs) and chlorinated phenolics.

In May and October, naphthalene, 2-methylnaphthalene, and 1-methylnaphthalene were the primary PAHs that were detected in the downgradient monitoring wells. In 1998, concentrations for naphthalene ranged from 0.012 to 0.027 mg/L, 2-methylnaphthalene from 0.0098 to 0.026 mg/L, and 1-methylnaphthalene from 0.0049 to 0.011 mg/L. PAH concentrations detected in 1998 are below standards for Safe Drinking Water Maximum Contaminant Levels (MCLs) of 0.2 mg/L. MTCA Method B (residential) cleanup standards have been established for carcinogenic PAHs (CPAHs) in groundwater beyond the facility boundary at 0.012 mg/L. In 1998, no PAHs classified as carcinogenic were detected in any of the monitoring wells. Naphthalene and 2-methylnaphthalene - as well as fluorene, phenanthrene and pyrene - were reported in 1997 as exceeding the MTCA Method B cleanup standard for CPAHs. None of these PAHs has been classified as carcinogenic and therefore does not exceed the cleanup standard.

Pentachlorophenol (PCP) was detected in MW-22 at an estimated concentration of 0.0033 mg/L in May and 0.0031 mg/L in October. PCP concentrations were below MTCA Method B cleanup standards of 0.729 mg/L. This is the first occurrence of PCP in any of the downgradient wells.

Most of the PAHs and chlorinated phenolics analyzed for were detected at both surface water stations during both sample events. All detected analytes in the surface water samples were far below established water quality criteria for fresh water (EPA 1992).

Link to EIM data for User Study ID CROSSARM