Presentation on theme: "Storm Water Pollution Prevention Plan (SWPPP) Discussion November 4, 2004 Resident Engineers meeting."— Presentation transcript:
Storm Water Pollution Prevention Plan (SWPPP) Discussion November 4, 2004 Resident Engineers meeting
Why write SWPPP National Pollutant Discharge Elimination System (NPDES) Phase II permit. Issued on August 1, 2003, the permit requires certain project owners to develop a SWPPP. Projects disturbing more than 1 acre require a permit and SWPPP. Phase I also had SWPPP requirements.
Prior SWPPP Implementation SWPPP requirements in permit. SWPPP to be written by Hydraulics/Water Resources. SWPPP information included in plan set. NPDES Permit Application completed by Design Engineers.
New Requirements Additional SWPPP requirements in permit. More emphasis on SWPPP. Contractors apply for NPDES Permit and are Co-permitees.
SWPPP Formats Stand alone documents, including appropriate plan sheets and forms. Tables in the plan listing NPDES requirements and their plan location. SWPPP as a checklist with NPDES requirements in the plan. SWPPP in several additional plan sheets with NPDES requirements in the plan.
STORM WATER POLLUTION PREVENTION PLAN (SWPPP) Project Description SP consists of grading, bituminous surfacing and a box culvert replacement on ¾ miles (total net length) of TH 112 south of Le Sueur, Mn. Construction activities include excavation and grading for realignment of the TH 112/CSAH 23 intersection located 3.5 miles south of the Le Sueur corporate city limits, and a box culvert replacement located 2.8 miles to the East of the TH 112/CSAH 23 intersection. The receiving waters for storm water from this project include a shallow marsh at the head of an existing creek/drainage ditch (realignment site) and Le Sueur Creek (box culvert site), none of which are classified as special waters. Project Engineer The Project Engineer and the Contractor are responsible for implementation of the SWPPP and the installation, inspection, and maintenance of the erosion prevention and sediment control BMPs before and during construction. MN/DOT District 7 staff and members of MN/DOTs Office of Environmental Service are also available for assistance. MN/DOT District 7 Maintenance is responsible for long term operation and maintenance of the permanent storm water management system. The MN/DOT Project Supervisor is;District 7 Maintenance Contact; Nathan GannonFran Bigaouette East Resident OfficeSub Area 1 SupervisorMN/DOT District South Victory Drive201 Minnesota St. Mankato, MN Le Sueur, MN (507) (507) Timing of BMP Installation The erosion prevention and sediment control BMPs shall be installed as necessary to minimize erosion from disturbed surfaces and capture sediment on site, and shall meet the NPDES Permit Part IV Construction Activity Requirements. Calculations Water quality volume New Impervious area 5.37 acres – 3.55 acres = 1.82 acres = 79,300 sq. Ft. Water quality volume 79,300 sq. ft * ½ in = 3,300 cu. Ft. WQ Volume The area of the bottom contour is 27,000 sq. ft. The inlet elevation of outlet structure is 927 Volume of pond is 27,000 sq. Ft. * (927 – 924.5) = 67,500 cu. Ft. The volume of WQ is more than the total volume required.
Should document be stand-alone or use references? How much time will be required to create a SWPPP using the various suggested formats? What exactly do the permits require? What works best for Mn/DOT? What works best for Mn/DOT Construction regarding enforceablity? What works best for Mn/DOT Construction & therefore contractors? What works best for MPCA? Will other's needs be met (MCEA, public, watershed districts, etc)? SWPPP Format Solution District H/WR Engineers 5/20/04
Solution Develop and utilize a process to ensure all needs of the permits are met 1. Use checklist to ensure all requirements are met. 2. Use cross reference table (CRT) mechanism as central communication method for SWPPP information. 3. Use "SWPPP folder / box" mechanism to contain all required info and enable access to information. "SWPPP folder / box" may be electronic or hard copy and will be the responsibility of district WR/H personnel. 4. Develop, fine-tune, and / or implement procedure for retention of "SWPPP folder / box, including amendments or changes to the SWPPP. 5. Develop, fine-tune, and / or implement procedure for reporting. SWPPP Format Solution District H/WR Engineers 5/20/04
To Do Solicit input from customers (construction, contractors, OES, MPCA) regarding documents needs. Solicit input from document writers (Hyd/WR, Design) on effort to meet permit requirements. Decide on format, checklist, etc. for a uniform statewide document or process.
SWPPP Format Solution District H/WR Engineers 5/20/04 In order to consistently produce a high-quality SWPPP, to facilitate & streamline review, and to meet all MS4 requirements as spelled out in the various permits, it has been suggested and largely agreed upon that a standard format for the SWPPP is required. To that end, several meetings have been held and numerous issues discussed. These issues include: Should document be stand-alone or use references? How much time will be required to create a SWPPP using the various suggested formats? What exactly do the permits require? What works best for Mn/DOT? What works best for contractors & therefore Mn/DOT Construction? What works best for MPCA? Will other's needs be met (MCEA, public, watershed districts, etc)? During and after these discussions, it has become apparent that no one format meets every district's needs. Most (or all) districts have incorporated the design requirement aspects of the MS4 permits into their workflow already. Several districts have in-place, well-working procedures for modification and retention of contract documents while other districts do not. Several districts do not have sufficient personnel to meet requirements imposed (actual or otherwise) by some of the formats. Some districts face added constraints that others don't and may not. For these and other reasons, the following solution is suggested. Solution Instead of focusing on an end format, develop and utilize a process to ensure all needs of the permits are met as part of the program delivery process as appropriate for each district while allowing variation (within certain constraints) in the end product. This method takes into account existing procedures that work well and proposes / enacts new procedures where none currently exist or are not working. It also allows but does not require use of any technologies, existing or new. It also leaves districts the ability to specify how to receive SWPPP info from outside parties (consultants and contractors). 1. Use checklist (based on work done to date by Katie Benik and Metro, input from MPCA (Todd Smith), and permit language) to ensure all requirements are met. Checklist to be available to all internal & external in electronic and paper formats. Checklist to be reviewed initially and annually (or as needed) by DistHyde. Checklist will be used by consultants on consultant design projects. 2. Use cross reference table (CRT) mechanism as central communication method for SWPPP information. CRT will refer to location of required and appropriate data as contained in the plan, specifications, special provisions, and any other project documents. CRT will incorporate all items from the developed checklist. CRT will be included in either plans or special provisions as necessary / appropriate. CRT will be used by consultants on consultant design projects. 3. Use "SWPPP folder / box" mechanism to contain all required info and enable access to information. "SWPPP folder / box" may be electronic or hard copy and will be the responsibility of district WR/H personnel. "SWPPP folder / box" must contain copy of plan set or at minimum all drainage related sheets (in order of preference: as-built, as-let, or as-designed), specifications, special provisions, and any other referenced or required project documents, including but not limited to SWPPP, SWPPP inspections and log, and SWPPP amendments. 4. Develop, fine-tune, and / or implement procedure for retention of "SWPPP folder / box". Strongly suggested that EDMS fill this role for ease of use and for reporting. 5. Develop, fine-tune, and / or implement procedure for reporting.