Summit County SWPPP Checklist: Concrete Washout & Excavation Compliance

The Rule: The Engineering Department mandates that sediment transport in runoff shall be prevented by using Best Management Practices (BMPs). The Summit County Nuance: Summit County explicitly requires that concrete washout areas must be provided on private properties where development involving concrete placement takes place. Because roadways and ditches in public rights-of-way must be kept clean at all times, relying on right-of-way space for washout staging is strictly prohibited.

The Rule: All finished grades steeper than 3:1 must be protected, and topsoil with native seed mix must be applied to all disturbed areas prior to the final grading inspection. The Summit County Nuance: The county's alpine weather drastically affects project closeouts. Summit County explicitly states that final grading and revegetation inspections are not possible during the winter months. If all site improvements (including washout removal and final stabilization) have not been inspected and approved prior to November 1, the county requires a Financial Guarantee to be posted before a Certificate of Occupancy will be issued.

The Rule: Grading and drainage plans must show existing topography at 2-foot contour intervals. The Summit County Nuance: If the site topography has greater than a 10% slope, the topographic survey must be prepared and stamped by a registered land surveyor. Because of these steep grades, temporary earth-disturbing activities (like digging a washout pit) are heavily scrutinized to ensure they do not exceed the maximum allowed 2:1 side slopes on finished contours. Any retaining structure over 4 feet tall required to support a washout or grading area must be engineered by a Colorado-licensed Professional Engineer.

The Rule: Protective fencing must be placed within the disturbance envelope before building or grading permits are issued, and it must remain intact throughout the entire construction process. The Summit County Nuance: Summit County severely penalizes careless equipment operation (such as a mixer truck or pump truck damaging trees while accessing a washout area). If any tree designated to be preserved is damaged during construction, the county dictates a 1:1 caliper ratio replacement. For example, damaging a single 12-inch caliper tree requires the contractor to purchase and plant three 4-inch caliper trees to satisfy the penalty.