DEP Project #: L-24441-24-A-N/L-24441-TF-B-N
Date: Thursday, 12-17-09 Time: 8:00-10:30 PM Report: 21
Observed by: Steve Roberge, PE Company/Agency: SJR Engineering Inc.
Weather Conditions: -6, 25 mph wind, very cold!
General Contractor: Reed & Reed Civil Site Contractor: Sargent
Clearing Contractor: DGD Trucking/JML Trucking & Excavating
Contacts onsite: Ray (Reed+Reed), Mark (Wagner), Tracy (Sargent), Dan
Date of Last Inspection: 12-10-09
Estimated # of days since last rainfall over ½”: more than a week
Photographs taken: 4 see attachments
The purpose of the site visit was to determine and document the effectiveness of the erosion control program being implemented at the project site and to insure the methods being used are being maintained. The site walk noted no significant erosion events.
Sargent continues installing/maintaining erosion controls along the cleared/skidded sections of ROW and construction access from Tower 22 to Tower 8. The JML crew is responsible for maintaining Tower 8 to Tower 1 access as well as the North End access up the mountain. They have completed towers/road from 1 through 3. Hay availability has been a problem. The contractor is switching to using erosion control mix (better than hay in my opinion) for cover material.
Maine Drilling and Blasting is operating full time at the site. Daily blasts (noonish) have occurred making rock available for road construction and slope stabilization. They are operating in the Tower 20 and Tower 16/17 areas of the Mine Notch Road.
Sargent has grubbed the main construction access road and the Mine Notch Road from tower 16 to Tower 22. Blasted rock has been used to construct the crane access road from Tower 22 to 14+00 and to approximately station 30+00 of the Mine Notch Road. This area is now under active construction and is drivable to pad 16. The construction access road has all upslope ditching with riprap permanent culverts installed (with the exception of stream culverts). Two level lip spreaders remain to be installed (likely next Spring). The Contractor is hay mulching disturbed soils at end of day’s activities.
The following items were inspected:
1. Silt Fencing: The Contractor dedicated a work crew to repairing/maintaining silt fence and adding fence where necessary in order to effectively shut down the project over the winter. The Contractor is keeping in mind that Spring conditions with snow runoff and Spring rains will contribute excessive amounts of water over the disturbed area.
2. Stabilized Entrance: The contractor has stone at the entrance to the project to minimize any tracking of soils. They have also installed additional crushed stone at the ends to bridges to minimize tracking of material onto the stream bridges and therefore into the stream.
3. Stockpile Area: Sand stockpiles have been created and surrounded with silt fence to capture any soils that may leave the pile. Other areas of stockpiles and final grading areas have mulch covering as winter conditions are present.
4. Mulching: Additional disturbed areas created during the construction activities this week have been cover with hay mulch Sargent and JML Construction continued covering sections of exposed soils with a heavy hay mulch application in anticipation of a winter shutdown. JML crews are switching from hay mulch to erosion control mix for cover material. The hay mulching operation was not effective due to the winds blowing the mulch off the surface to be covered.
5. Erosion Control Mix: Many of the water bar outlets have erosion control mix or crushed stone installed to collect sediment. The erosion control mix at the outlet end of the water bars capture significant amounts of sediment in the grubbed areas of the crane access road. These have been cleaned and prepared for the next storm event. The Met Tower access road will have outlet protection such as the erosion control mix or stone check dams depending on the flow of water across the bars once the road freezes in.
6. Dust Control: Not needed at this time.
7. Hay Bales: Hay bales have been installed in conjunction with silt fence in the areas near resources and along the downslope side of construction for the access road. This meets the requirements for double barriers protecting resources during winter conditions. Most of the hay bales are better used for mulching purposes.
8. Stone Check Dam: The existing gravel access road has water bars with check dams being located in the ditch lines. The ditching along the upslope side of construction has stone check dams. The Contractor has all ditching lined with riprap along the construction access road and portions of the Mine Notch Road to station 30+00.
9. Culverts/Riprap: IF&W has not permitted an extension to the time window for installing culverts within streams. Other culverts have been installed within drainage paths as called out on the plans. All of the culverts have riprap inlet/outlet protection. Some of the larger culverts have a stone level spreader at the outlet end to disperse the water over a larger buffer area. The steam culverts are the only remaining pipe to be installed (to be completed in next year’s time window).
10. Level Spreader: Level spreaders have been constructed in several locations along the construction access road. Two remaining spreaders will be installed next year along the construction access road.
11. Water Bars: The gravel access road has erosion control devices such as drivable water bars with stabilized outlets (stone and/or erosion control mix check dams) being located along the steeper portions of the entrance road. Many additional water bars are located in the grubbed construction access road to allow upslope water easy passage across disturbed soils. The water bars have erosion control mix installed along the outlet end of the bars.
The Met Tower access road has been closed out (restored) for the full length of the road. The Contractor has installed many water bar diversions. The bars do not have any outlet protection such as rock check dams or erosion control mix installed at the end of the bars. The sediment in the existing ditch turnouts has not been cleaned. The Contractor will perform these tasks once the road freezes in to limit damage to the existing restored areas.
12. Catch Basins/Stormdrain system: All culverts (except in streams) have been installed along the construction access road and from pads 18 through 22.
13. Ditches/Swales: The gravel access road is being managed with proper erosion control devices including check dams being located in the ditch lines. The Contractor continues lining ditch bottoms with geotect fabric and riprap stone along the Mine Notch Road.
14. Groundwater seeps/Hidden Channels: The Contractor should continue to review locations where seeps are visible. These should be marked for future considerations with regard to how the access roads are constructed (rock sandwich).
15. Cut/Fill Slope Protection: The Contractor has hay mulched disturbed soils throughout much of the active working project. Skidder trails have brush and/or corduroy placement in locations of steep slopes to minimize erosion at other locations. The Contractor has devised a system of water bars, bypass culverts/ditches, and sediment containment areas to limit erosion and sedimentation along disturbed soils. Construction of the Mine Notch Road from station 30+00 to tower 22 has a rock base. The Construction access road is completed with the exception of a few permanent culverts. Active work in the crane access road leading to pad 17 has new erosion control blanket installed.
16. Vegetative Cover: Not applicable at this time.
17. Stream/Wetland Crossings: Bridging streams and matting wetlands are the only acceptable means for crossing at this time. IF&W has not extended the stream culvert placement window for this project. All in-stream work must be conducted between July 15 and September 30.
18. Spill Prevention: No evidence of any spills has been noted during this visit.
19. Winter Construction: The Contractor has been under winter construction requirements since November 1, 2009. The Contractor is preparing the project for a winter shutdown anticipated to occur on January 9, 2010 (weather permitting). It is still unknown whether the collector line clearing/skidding operation will continue forward during the winter months.
20. General nature of project: The project erosion control activities are current with the active work operations. Skidder trails 1+2 and the existing Met tower access road are restored and closed to traffic. The north access skidder trail (tower pads 1-8) has been partially mulched and should be completed by the end of December.
21. Areas currently under construction/disturbance: Clearing activities and bridge construction over streams have been performed from station 1+00 along the construction access road to the Tower pads 16 through 22 including crane access road. The clearing crew has cut/skidded the main construction access road and Mine Notch Road from tower 1 to tower 22 and is finished until frozen ground conditions are present. The ROW has been cut along the crane access road full length. Active construction is mostly contained in the tower 20, towers 16/17, and crane access road from station 30+00 leading to tower 16.
22. Estimate total area under construction/disturbance: Station 1+00 through 80+00 of the construction access road building has completed construction. Grubbing has occurred from tower 16 to tower 22 locations with the rock fill being placed along the road and towers 18 through 22 and to station 30+00 of the Mine Notch Road. Clearing/skidding operations are completed along the crane access path from one end of the project to the other. The Contractor has cut/skid/decked trees along the ridgeline from Tower 1 through Tower 12 and will bring them down the mountain along the crane road as it becomes available. The contractor is mulching the skidder trail along the ridgeline from towers 1-8, and has completed mulching the clearing/skidding/stumping disturbed areas from 8-15. Active construction/drilling/blasting is occurring in the Mine Notch Road from station 30+00 up to pads 16/17.
23. Comments: The erosion control program is effective and is being implemented as needed and necessary to control erosion during the construction of the project. The site is pretty much frozen in at this point of time. Frost under the crane access road is 18” deep and variable under the snow cover.