| October 11, 2005
| The Turnpike Authority responded to concerns that I mentioned in an earlier informal working group meeting by asking to visit the site in East Boston where we believed there was a problem. Christian and I visited along with Rick McCollough of the MTA. The house, the backyard of which overlooks the entrance to the Sumner Tunnel, has a test pit that shows severely deteriorated pilings. The MTA is gathering information to better assess what might be happening there. |
| November 17, 2005
| The Turnpike Authority has done further investigation of the retaining wall at the Sumner Tunnel entrance in East Boston but has not yet discovered any apparent leakage that may be causing low groundwater levels there. They have conducted video surveys of their drains near Herald St and Chandler St to see if they have any leakage that could be depressing groundwater levels. In addition, we have now been given a list of remaining artery wells. Christian has examined the wells, and it looks like we will be incorporating five additional wells into our system. |
| January 11, 2006
| The Turnpike Authority has hired a consultant to evaluate the information discovered during their investigation of the Sumner Tunnel approach in East Boston for potential leakage. We will get a copy of the report; no current leakage is indicated, and the approach was built as a waterproof wall with no drainage. The MTA will also be evaluating approaches to the Callahan Tunnel in the North End in response to reports of reduced groundwater levels in that area. They have found one relatively small leak in their structure in the area near Herald Street, which will be repaired. This could be the cause of low groundwater in that area. The CA/T will make final arrangements to turn over to us five wells that we have identified as potentially useful to our network. |
| March 22, 2006
| The Turnpike Authority remains committed to repair of the leak discovered in their drain near Chinatown; a contract should be let shortly. They have completed an analysis of their drains at the East Boston ends of the Sumner and Callahan Tunnels that did not indicate any leakage or dry weather flows. The retaining wall was designed without underdrains. The MTA will be studying the North End connections to those tunnels to look for any potential leak locations. |
| April 27, 2006
| The MTA found a small leak (about 1 gallon/minute) in a Callahan Tunnel abutment near North Street; it should be repaired within 4-6 weeks. There were no leaks around Sumner Tunnel connections in the North End. They expect to take bids for repair of the leak in the drain near Herald Street within four weeks. |
| June 5, 2006
| The MTA will be taking bids soon on a project to renovate the Sumner/Callahan vent buildings in East Boston and the North End. As part of the project, they will install recharge systems for both. They will also include relining the pipes near Herald Street that had some leakage as part of the same package. They are also working on a project to clean and video their main trunk line between the Prudential Center and Pump Station 7. They will then video the line; there is some indication of small leaks in the vicinity of Exeter and Huntington that could need repair. In the North End, they are close to hiring a contractor to repair a leak in the approach to the Callahan Tunnel that could be drawing down groundwater. |
| July 17, 2006
| The MTA is taking final quotes on the repair of the leak in their drain near Herald Street. This work should be done in the next couple of months. They are still studying the details of recharge systems to be installed during reconstruction work on the North End vent buildings for the Callahan and Sumner Tunnels. They do not yet have a time frame for the repair of a leak in a wall of the approach from I-93 to the Callahan Tunnel. |
| September 20, 2006
| MTA groundwater repairs have slipped somewhat as their focus has been on the tunnel ceiling repairs. The new leadership of the Authority hasn’t yet focused on the problem. However, the MTA remains committed to the repairs and is scheduled to brief me on current status on Sept. 22. |
| October 26, 2006
| MTA has repaired the small leak in the connector from I-93 to the Sumner and Callahan Tunnels. They have issued a contract for repairs to a leak in their drain line near Herald Street. They plan to include recharge in their roof drain repair project at the East Boston vent buildings for the Sumner and Callahan Tunnels. In conjunction with the Columbus Center project, they plan a major inspection of the drain line running inbound from the Prudential Center to look for any leakage. |
| January 18, 2007
| The repairs at Harrison Avenue appear to have had a positive impact on nearby groundwater levels. We should be able to better confirm this in our current set of readings. |
| February 15, 2007
| The MTA will be inspecting its drains in the area of Exeter Street and Huntington Avenue when the weather warms. There has been a drop in levels at that corner in recent months. |
| March 22, 2007
| The MTA will be inspecting its drains in the area of Exeter Street and Huntington Avenue when the weather warms. There has been a drop in levels at that corner in recent months. |
| April 23, 2007
| The MTA hopes to inspect its drains in the area of Exeter Street and Huntington Avenue this week. There has been a drop in levels at that corner in recent months. |
| May 14, 2007
| The MTA has inspected its structure near Prudential, but has yet to find any leaks there. |
| October 25, 2007
| The Turnpike has inspected the plenum that runs below the Central Artery and have not found any signs of groundwater leakage. This covers the area between the Zakim Bridge and Commercial Street. They are trying to work out a way to remotely monitor the pumps located at the midpoint of the Sumner and Callahan Tunnels to determine if they are pumping during dry weather. They will also do additional monitoring of the drains in Back Bay as the Columbus Center construction gets going to see if there is anything that could be lowering groundwater levels, especially in the area around Exeter Street. |
| November 29, 2007
| The Turnpike is still awaiting turnover of the remaining groundwater equalization systems along the Artery. They may want our assistance in surveying elevations of the system inlets. |
| May 29, 2008
| The MTA is working on a Notice of Project Change related to the amount of water discharged from the Central Artery and Ted Williams Tunnel to the MWRA system. They have been encouraged by MEPA to work with us on potential recharge at appropriate locations. They will look into potential recharge from low points near Chinatown, the Leather District, and the North End. |
| July 31, 2008
| The Turnpike Authority has discovered two leaking manholes in the area where BWSC injected dye to discover a potential cause of low groundwater levels in a section of the North End near Cross Street; the manholes are expected to be repaired within two weeks. The MTA has issued a Notice of Project Change to modify some of their drainage systems from the Central Artery/Tunnel project; they will be studying potential recharge at three of the locations to be modified. |
| August 29, 2008
| The Turnpike Authority has repaired one of the leaking manholes in the North End and is working on the other. We have data loggers in several nearby observation wells and will be watching levels closely. |
| September 25, 2008
| The MTA has done a partial inspection of the tunnel section between Berkeley and Clarendon Streets and found dry weather flow coming from a reinforced concrete pipe section; they anticipate that the repair will be straightforward and will schedule it shortly. They will be inspecting the drain line flowing from the Prudential tunnel eastward shortly for possible dry weather flow. Repair work in the North End is nearing completion. |
| October 27, 2008
| In the North End, the MTA has completed the repairs to the manhole in the ramp closest to Cross Street, is nearing completion of the repairs to the manhole on the ramp on the opposite side of the tunnel, and has identified a third manhole for inspection in the grass area above the roadway. The MTA has inspected their main 52" drain line in the area near the low groundwater reading under the Clarendon Street bridge and found it to be tight; however, they have found dry weather flow in an 18" branch pipe between Columbus Avenue and Clarendon Street and will schedule it soon for repair. The MTA is in the process of hiring a consultant to determine whether they can effectively divert some of the rainwater/groundwater drainage from certain CA/T pump stations to recharge, as discussed in their recently filed Notice of Project Change for redoing the drainage system. |
| November 20, 2008
| The MTA hopes to make the repairs to the pipe near Clarendon St in December. |
| January 29, 2009
| The MTA has completed the repairs to three manholes along and above the Central Artery in the North End. Within two months, they expect to complete repairs to a drain line from the Turnpike near Clarendon Street. They have inspected their drains in the Prudential Tunnel area and have found no signs of leakage. |
| March 2, 2009
| The MTA expects to complete the repairs to leaks in a drain line near Clarendon Street by April. |
| March 26, 2009
| The MTA expects to complete the repairs to leaks in a drain line near Clarendon Street in the near future. |
| April 29, 2009
| The repairs to the MTA drain line near Clarendon Street and Columbus Avenue are expected to be complete within about a month. They have approval for funding and have hired a consultant to design the redirection of drain lines from the Big Dig; the project will investigate the potential for recharge at several locations identified by the Trust. |
| May 28, 2009
| The repairs to the MTA drain line near Clarendon Street should be completed this week. |
| June 29, 2009
| The repair work done on the drain line near Clarendon St did not solve the problem. MTA is working with their contractor to determine a further fix. |
| July 30, 2009
| The MTA will be conducting a dry weather inspection of the North End repairs in August to assure that they have solved the leak. The repair at Columbus Ave and Clrendon St was only partially successful; MTA and their contractor are working on a further solution. MTA will be setting up an advisory committee on groundwater implications of their planned Central Artery drainage changes in September. |
| August 26, 2009
| Repair work to the leak near the corner of Clarendon Street and Columbus Avenue was scheduled to be completed last week. |
| September 24, 2009
| Repairs to the leak near the corner of Clarendon Street and Columbus Avenue were completed in early September. |
| October 27, 2009
| The MTA (making its final report before it is absorbed into the new Department of Transportation next month) has completed repairs to the leak near Clarendon Street and Columbus Avenue. Our two closest wells both showed significant increases in our recently completed round of readings. The MTA will convene a meeting of the City-State Groundwater Working Group’s Technical Advisory Committee in the near future to discuss the potential for recharge related to some replumbing of drainage from the Central Artery at locations near Chinatown, the Leather District, and the North End. |
