B08 Attachment 0003 Appendix B - Monitoring Well Information.pdf

APPENDIX B

Required Modifications to Existing Monitoring Wells According to the construction drawings currently developed, there are four sets of monitoring wells (MWs) that will require modifications due to the road construction. These are the MW-3 cluster of MWs (MW-3S, MW-3D, and MW-3DS), MW-7 cluster (MW-7S and MW-7D), MW-8, and the MW-12 cluster of MWs (MW-12S, MW-12D, and MW-12DR) for a total of nine individual MWs. The MW-12 cluster and monitoring well MW-8 will be affected by the new location of Beck Avenue while the MW-3 cluster and MW-7 cluster will be affected by the new frontage road (Flagler). All of the MWs are planned to be on or near the shoulders of the new roads, except for the MW-3 cluster, which will be in the middle of the new frontage road (Flagler) near the intersection. The MWs on or near the shoulders shall be raised except the MW-12 cluster, which shall be lowered. The MW-3 cluster of MWs shall be converted from stick-up MWs to flush mount MWs. The well modification activities shall be conducted by a well drilling company that installs monitoring wells and must be in accordance with all applicable Federal, State, and local laws, regulations, policies, and guidance. The well drilling contractor must follow the regulations and requirements set forth in the Illinois Department of Public Health, Subchapter r: Water and Sewage, Part 920 Water Well Construction Code, Section 920.170 Monitoring Wells, subsections (a) and (d)(3) regulations. Other example guidance that may be used by the Contractor includes but shall not be limited to:

• USACE Engineer Manual 1110-1-4000, Monitoring Well Design, Installation, and Documentation at Hazardous, Toxic, and Radioactive Waste Site.

• USEPA ERT SOP ERT-PROC-2048-20, Groundwater Monitoring Well Installation

• USEPA Guidance Number SESDGUID-101-R2, Design and Installation of Monitoring Wells.

• ASTM D5978, Standard Guide for Maintenance and Rehabilitation of Groundwater Monitoring

Wells.

• ASTM D5092, Standard Practice for Design and Installation of Groundwater Monitoring Wells.

The required modifications to each MW or set of MWs are identified below:

MW-3 Cluster of MWs (3 MWs made flush)

1. The bollards and protective steel casings around each of the three MWs shall be removed.

2. Each 2-inch PVC MW casing shall be cut down (level cut) to an elevation that shall be between five to eight inches below the future road grade elevation.

3. Each MW shall require a new J-plug on the 2-inch PVC casing.

4. Install a new steel flush mount well box on top of each 2-inch PVC monitoring well with the top of the flush mount well box to be flush with the future road grade elevation. The flush mount well boxes shall be of traffic rated design to meet or exceed H-20 and AASHTO M306 roadway loading requirements. They shall be 12-inch x 12-inch bolt down or twist lock well boxes.

5. Each flush mount well box shall be set in a 2-foot x 2-foot concrete pad with a minimum thickness of 9 inches.

6. The new elevation of both the concrete well pad and the top of the new casing shall be surveyed. The north side of the rim of the well box and the well pipe are the sides to be surveyed.

MW-7 Cluster of MWs (2 MWs raised)

1. The bollards and protective steel casings around each of the two MWs shall be removed.

2. Each 2-inch PVC MW casing shall be raised to an elevation that shall be between three and four feet above the future shoulder elevation. Adding the additional pipe length shall require the use of a compression fitting at the connection of the current well pipe and the new well pipe. No glued joints are allowed. The top of the well casing is to be level and not angled.

3. Each MW shall require a new J-plug on the 2-inch PVC casing.

4. Each MW shall require a new protective stick-up well casing that is square in shape, with a lockable lid. The stick-up is to be set in a 2-foot x 2-foot concrete pad, at least four inches in thickness and painted yellow.

5. Three bollards shall be placed in concrete around each monitoring well. Each bollard shall stick up between four and five feet above ground surface. Each bollard shall be painted yellow. The monitoring well ID shall be painted facing out on one of the bollards.

6. The new elevation of both the concrete well pad and the top of the new casing shall be surveyed. The north side of the well pipe is the side to be surveyed.

MW-8 Monitoring Well (1 MW raised)

1. The bollards and protective steel casing around the MW shall be removed.

2. The 2-inch PVC MW casing shall be raised to an elevation that shall be between three and four feet above the future shoulder elevation. Adding the additional pipe length shall require the use of a compression fitting at the connection of the current well pipe and the new well pipe. No glued joints are allowed. The top of the well casing is to be level and not angled.

3. The MW shall require a new J-plug on the 2-inch PVC casing.

4. The MW shall require a new protective stick-up well casing that is square in shape, with lockable lid. The stick-up is to be set in a 2-foot x 2-foot concrete pad, at least four inches in thickness and painted yellow.

5. Three bollards shall be placed in concrete around the monitoring well. Each bollard shall stick up between 4 and 5 feet above ground surface. Each bollard shall be painted yellow. The monitoring well ID shall be painted facing out on one of the bollards.

MW-12 Cluster of MWs (3 MWs lowered)

1. The bollards and protective steel casings around each of the three MWs shall be removed.

2. Each 2-inch PVC MW casing shall be lowered to an elevation that shall be between three and four feet above the future shoulder elevation. Removal of the required amount of well pipe shall be done using an internal plastic well pipe cutter. The top of the well casing is to be level and not angled.

3. Each MW shall require a new J-plug on the 2-inch PVC casing.

4. Each MW shall require a new protective stick-up well casing that is square in shape, with a lockable lid. The stick-up is to be set in a 2-foot x 2-foot concrete pad, at least 4 inches in thickness and painted yellow.

5. Three bollards shall be placed in concrete around each monitoring well. Each bollard shall stick up between four and five feet above ground surface. Each bollard shall be painted yellow. The monitoring well ID shall be painted facing out on one of the bollards.

If other MWs require modifications, the Environmental Restoration Manager (ERM) (Scott Adner) in the Department of Public Works shall be notified to determine what modifications are required. For any other MWs that are damaged during construction activities, the ERM shall be notified to determine extent of damage and the contractor shall be responsible for the repairs. If any MW at the site is damaged beyond the point of repair during construction activities, the contractor shall be responsible to abandon the current MW, install a new MW adjacent to the destroyed MW to the same depth as the one to be replaced, develop the new MW, survey the new MW, and submit the required paperwork to the IDPH. The MW drilling work shall follow the requirements of the IDPH, Part 920 Water Well Construction Code, Section 920.170 Monitoring Wells.

Well Redevelopment With the modifications to the nine MWs, the possibility of debris falling in the MWs during modifications, and the possibility of damage to the remaining six MWs (MW-1, MW-2S, MW-2D, MW-4, MW-5, and P-1) during construction activities at the site, all fifteen site MWs shall be redeveloped after construction activities are completed. A map showing the locations of fifteen MWs is provided. This work is to be conducted by a well drilling contractor and the contractor shall complete the monitoring well redevelopment in accordance with all applicable Federal, State, and local laws, regulations, policies, and guidance. Example guidance that may be used by the Contractor includes but shall not be limited to:

• USACE Engineer Manual 1110-1-4000, Monitoring Well Design, Installation, and Documentation at Hazardous, Toxic, and Radioactive Waste Site.

• USEPA Environmental Response Team (ERT) Standard Operating Procedure (SOP) ERT-PROC- 2044-20, Monitoring Well Development.

USEPA ERT SOP ERT-PROC-2048-20, Groundwater Monitoring Well Installation

• USEPA Guidance Number SESDGUID-101-R2, Design and Installation of Monitoring Wells.

• ASTM International (ASTM) D5521, Standard Guide for Development of Groundwater Monitoring

Wells in Granular Aquifers.

• ASTM D5978, Standard Guide for Maintenance and Rehabilitation of Groundwater Monitoring

Wells.

• ASTM D5092, Standard Practice for Design and Installation of Groundwater Monitoring Wells.

At a minimum, five well volumes must be removed from each MW. Additionally, field water quality parameters shall be taken during development until parameters have stabilized according to the following:

• Temperature ± 10% for three consecutive readings

• pH ± 10% for three consecutive readings

• Specific Conductance ± 10% for three consecutive readings

• DO ± 10% for three consecutive readings

• ORP ± 10% for three consecutive readings

• Turbidity = 5 NTUs as a goal; additional purge time may be required in attempt to reduce turbidity

If a well is pumped dry, it shall be allowed to recover. No agents or additives shall be used or introduced into the well during development or at any other time.

Munitions and Explosives of Concern There is the potential for Munitions and Explosives of Concern (MEC) to be presence near the southwest corner of Building 250. In September and October of 2020 a total of five inert 40mm grenades were discovered there during construction activities adjacent to the building. If during construction activities MEC is discovered, work should stop immediately, the area evacuated, and the Contracting Officer’s Representative (COR) notified so that Emergency Services and the Bomb Squad can be notified to remove the MEC and a path forward can be determined.

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