R-3300B Field Review Summary 20230329

R-3300B Hampstead Bypass
Summary of field review 3/28/2023
The following issues were first reported after the project was reviewed on 3/27/2023 after receiving
approximately 2.4 inches of rain in the previous 24 hours. All crews on-site were actively addressing
these issues.
Area 1 Site 19 Approx. Sta. 18+00 -Y32-
• Berm failed causing sediment to flow into “new JS.” This new JS is the channel which is
temporary (and fabric lined) and carries jurisdictional waters. The area where sediment entered
the JS from a plastic pipe has been cleaned up. They will need inlet protection at this plastic
pipe. They are planning to replace a section of fabric which was damaged. As the water level
goes down they will try to clean sediment off of the fabric.
Area 2 Site 19 Approx. Sta. 19+25 -Y32RPB1- 225’ Rt.
• Water flowing out of the woods caused silt fence to be undermined. This contributed sediment
to channel (near outlet of 78” pipe). They will add an outlet here - a break in the silt fence with
hardware cloth and stone (special sediment control fence).
Area 3 Site 19 Approx. Sta. 17+64 -Y32RPB1
• This location is in the vicinity of the outlet of the 78” pipe. There was turbidity leaving a 36”
pipe flowing down a ditch and into the JS at the outlet of the 78” pipe. This was causing
turbidity in the JS channel down gradient of this area. While onsite, this flow was blocked with
an earth dam. This should decrease the turbidity in the JS. They will investigate why turbid
water was leaving the 36” pipe.
Area 4 Site 19 Approx. Sta. 28+00 - Sta. 29+25 -Y32 LT (4 total locations)
• SDO was overwhelmed and resulted in sediment in JS. Crews were cleaning this up with hand
tools. There were 3 other locations which had sediment plumes in the JS. Crews were planning
to remove the sediment from all areas yesterday. This sediment did not seem to be causing
turbidity in the JS.
Area 5 Site 19 Approx. Sta. 29+00 -Y32- LT
• Water flowing out of the woods (upstream of the 78” pipe) undermined silt fence. Crews will
remove sediment and add an outlet here - a break in the silt fence with hardware cloth and
stone (special sediment control fence).
Area 6 Site 14 Approx. Sta. 725+00 -L1-
• The fill which was used for a temporary pipe crossing in a JS non mit collapsed and caused
turbidity downstream. The location where the fill collapsed will be permanently impacted, but
the permanent pipe has not been completely installed yet. A crew was onsite adding rock to the
slopes of the temporary crossing. We will have to review the site again to make sure that the
turbidity in the JS non mit has settled out.

Area 7 Site 13 Culvert 13 Approx. Sta. 712+50 -L1-
• A diversion had been recently installed at this culvert site. During the rain, the corner of the
diversion failed and water went around the impervious dike into the old JS. This also seemed to
create turbidity in the division channel (which has the JS flow in it). They will repair the washed
out area at the impervious dike. The turbidity seemed to have already decreased from when
the original photos were sent.
Area 8 Site 3 Culvert 10 Outlet Approx Sta. 26+00 -SR6-
• Water which ponded behind the wingwall weephole caused a loss of turbid water into riprap
and the JS at outlet of culvert. This was addressed with a sand bag at the wing wall and
additional silt fence around the riprap. Also, washed stone will be placed at weephole.
Additional weepholes along the culvert will have to be addressed if the area is not brought up to
grade soon.