Groundwater Professional Bulletin Board

POSTED: 07/10/2008

Groundwater Sampling Schedule Revised Due to Floods of 2008

The floods of 2008 have affected a significant portion of the state of Iowa. If you are the certified groundwater professional for a leaking underground storage tank (LUST) site that has been flooded, please contact the DNR project manager. Let the project manager know which site has been flooded and any other pertinent information you may have about the condition of the site.

In response to the floods the DNR is revising the annual groundwater sampling requirements for 2008 by extending the monitoring and reporting schedules. The purpose of the time extension is to allow the static water level to return to pre-flood levels so groundwater samples can be collected from within the screened portion of the existing monitoring wells. Groundwater samples collected when a well screen is submerged are not valid and should be ignored in the software.

If it is determined the well cap (J-Plug) was not secure, a slotted/perforated well cap was in place, or well subsidence or well heave are noted, the monitoring well should be developed (re-developed) prior to sampling to repair possible damage to the surrounding formation.

If a LUST site is currently classified low risk the annual monitoring may be done during the fourth quarter instead of the third quarter of 2008. The 2008 Site Monitoring Report is due by 01/30/09.

If a LUST site is currently classified high risk and has been affected by flooding please contact the DNR project manager to discuss the site specifics and develop a revised activity schedule. There may be sites where remediation system components have been damaged by flooding such that the system has stopped operating. Prior to replacing equipment and restarting the system, the effectiveness of the treatment system (pre-flood) should be evaluated. Post-flood soil and groundwater conditions should also be determined.

If you have questions, please feel free to contact Elaine Douskey at (515)281-8011 or elaine.douskey@dnr.iowa.gov .