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Groundwater Professional Bulletin Board POSTED: 08/02/2000Questions Presented at the Meeting with Consultants on July 20, 2000The following provides clarification for questions raised at the meeting with
groundwater professionals at DMACC on July 20, 2000.
Activities conducted to document a plastic water line replacement (service or transmission lines) may be recorded in a Site Monitoring Report, Corrective Action Design Report, or Tier 2 Site Cleanup Report Addendum. Our expectation is the certified groundwater professional will supervise the replacement. We would encourage consultants to be involved in the replacement activities to ensure the correct length of pipe is replaced. Consultants should take into consideration uncertainties in plume definition when determining the replacement length. Reference Section 5.7 of the Tier 2 Guidance for additional information on this subject. If metallic lines are installed, petroleum-resistant gaskets must be used. Original plastic water lines left in place after the replacement should be plugged at
the ends. The original plastic water line utility envelope should be evaluated for the
potential to act as a preferential pathway for contamination migration.
The operational life of a vapor monitoring well used to sample soil or groundwater
vapors is considered to be two sampling events. Every time the well is sampled it is
considered a sampling event. For example, a soil gas sampling followed by a
confirmation sample are considered as two sampling events.
Contact Elaine Douskey at (515)281-8011 or elaine.douskey@dnr.state.ia.us if you have questions concerning this posting. |
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