Because Contractor Report has documented 13 sediment spills into Monona Bay, plus one extreme dust incident, it's beyond question that either the plan below, and/or its implementation, were flawed. But Ghidorzi and the City signed on to this plan, so knowing the plan is where any investigation starts. Later, we plan to post a critique of this plan, plus detailed analysis of how it was carried out.
Wingra Clinic--Grading, Erosion Control, and Landscaping Plans C 2.0
By Engineer Wade P. Wyse
Obtained from DNR via a Freedom of Information Request
"General notes" (relevant parts)
6. All building and waste materials shall be properly handled and disposed of offsite to prevent runoff of material into waters of the State.
"Construction Site Erosion Control Requirements"
I have emphasized in blue the items easiest to observe from outside the site
- All erosion and sediment control practices shall be designed and implemented in accordance with the current department of natural resources erosion and sediment control technical standards which are available at http://www.dnr.state.wi.us/runoff/stormwater/techstds.htm
- Install erosion control measures prior to any site work, including grading or disturbance of existing surface materials as shown on plan. Modifications to sediment control design may be conducted to meet unforeseen field conditions if modifications conform to WDNR technical standards.
- Inspections and maintenance of all erosion control measures shall be routine (once per week minimum) to ensure proper function of erosion control at all times. Erosion control measures are to be in working order at the end of each work day.
- Inspect erosion control measures after each ½’ or greater rainfall. Repair any damage observed during the inspection.
- Erosion control measures shall be removed only after site construction is complete with all soil surfaces having an established vegetative cover.
- Install a tracking pad 50’ long and no less than 12” thick by use of 3” clear stone. Tracking pads are to be maintained by the contractor in a condition which will prevent the tracking of mud or dry sediment onto the adjacent public streets after each working day or more frequently as required by the city of Madison.
- Install erosion controls on the downstream side of stockpiles.
- Install check dams within drainage ditches and in front of silt fencing in any low area all in accordance with WDNR technical standards.
- Erosion control for utility construction (Storm sewer, sanitary sewer, water main, ETC.): A. Place excavated trench material on the high side of the trench. B. Backfill, compact, and stabilize the trench immediately after pipe construction. C. Discharge trench water into a sedimentation basin or filtering tank in accordance with the dewatering technical standard No. 1061 prior to release into the storm sewer, receiving stream, or drainage ditch.
- Install type D inlet protection around all storm sewer inlets and catch basins that may receive runoff from areas under construction. Refer to WISDOT FDM for respective details.
- Apply anionic polymer to disturbed areas if erosion becomes problematic.
- Dust shall be controlled on the site per WDNR storm water management Technical Standard 1068 if necessary.
- Additional erosion control measures as requested by state inspectors, local inspectors, and/or engineer shall be installed within 24 hours of request.
- All slopes exceeding 4:1 (25%) shall be stabilized with Class I, Type B erosion matting and drainage swales shall be stabilized with a Class II, Type B erosion matting, or application of a WDOT approved polymer soil stabilization treatment or a combination thereof, as required. Contractor shall provide product specifications to project engineer for approval.
- Contractor/owner shall file a notice of termination upon vegetative stabilization and/or property sale in accordance with WDNR and WDCOMM requirements.
- Dewatering, if applicable, shall be conducted per WDNR storm water management technical standard 1061.
1. All disturbed areas shall be seeded and mulched immediately following grading activities. Seed mix to be in accordance with landscape plan.
Details shown on the engineering drawing (in my words)
- The silt fence completely surrounds the site, except at the NE corner, from Park St. to the construction entrance on Midland St.
- Three construction entrances are shown: One on Park St. (not used, to our knowledge), one on Midland St., and one on Fish Hatchery Rd. All refer to the standard specs for size and maintenance (item 6).
- The N tip of the triangle, at the junction of Fish Hatchery and Park, is to be left undisturbed.
- Nowhere on the plan did I see any statement that it was permissible to replace sediment fence with silt socks.