Minutes of April 9, 2003
PLANNING BOARD:
Ross McLeod, Chairman – Present Wayne Morris, Vice Chairman – Present
Lee Maloney, Secretary – Present Roger Hohenberger, Selectmen Member – Present
Walter Kolodziej, Regular Member – Excused Nancy Prendergast, Regular Member – Present
Pam Skinner, Regular Member – Present Roy Dennehy, Alternate – Excused
Christopher Doyle, Selectmen Alternate – Present
BOARD OF SELECTMEN:
Galen Stearns
Bruce Bretton
OTHER ATTENDEES:
Randall Shuey – Gove Environmental
Dave Paulsen, Chair – Surface Water Committee
Al Turner and Walter Warren – Windham Planning and Development
Dianna Fallon – Conservation Commission
Russ Wilder
Carl Dubay, MHF Design
Mr. Morris opened the meeting at 7:30 p.m.
Mr. Shuey provided an overview of the EPA’s National Pollutant Discharge Elimination System (PDES), Best Management Practices and Real World High Order Treatment using slide presentation.
Storm Water Regulations: Discussion of erosion and its control, distinguishing natural v. accelerated erosion, the purpose of stone layers under the soil, the Clean Water Act and the effects of sediment and the increase cost to the town to maintain sediment effects. Discussion of regulatory requirements for permitting: Water Quality Certification required for federal permit; Discharge Dredge and Fill regulated by Army Corps of Engineers.
Storm Water Pollution Protection Plan (SWPPP) covers areas of 5 or more acres under Phase I and up to 5 acres under Phase II.
Less than 3 acres of wetland fill permitted and falls under jurisdiction of NHDES Wetlands Bureau. Notice of intent (NOI) required when filing for a fill permit under the SWPPP.
Requirements of NH Site Specific v. NPDES applications: 2.3 acres of contiguous area to be disturbed v. 1 acre cumulative area; 1 permit per developer v. multiple permits per developer; 2 –3 months of formal review v. 48 hrs. prior notification; complete application process v. 1 page NOI.
SWPPP on construction sites, must file NOI, multiple permits, and monitor and keep records. SWPPP serves as a guide or blueprint, is a basis for communication and allows flexibility. SWPPP goals to characterize site, identify potential pollutants, provide Best Management Practices (BMP) and, provide for inspection and maintenance as well as a means to update plans. Bringing SWPPP to local level includes wetlands setbacks, no-cut zones, and aquifer protection zones. Final ground stabilization is considered when site is 70% covered with vegetation.
Under SWPPP 10 acres of open land needs to have sediment retention area, provide temporary ground cover and implement BMPs.
Best Management Practices erosion control include runoff controls, erosion controls, vegetative and non-vegetative covers, silt fencing, hay bales and sediment stop (wattles). Silt fencing is not meant to be permeable; trenches with gravel need gentle slopes if size of the area is ¼ acre, max. flow length is 100-foot slope; space silt fences off the toe of the slope and provide a mechanism for the removal of the fence. Hay bales placed in a trench 4 inches into ground, 2 stakes per hay bale, string on side, placed on level area (2:1 grade) max. length 100 feet. Sediment stop (Wattles) are rolls filled with wood fiber, provide a splash apron, improves soil contact and are used for gully remediation on steep slopes imbedded in a shallow trench and placed 40 feet apart. Construction entrances with rock, 2 – 4 inches of stone, 50 feet in length. Silt and hay bale combos.
Mr. Paulsen suggested that developers be notified when we have workshops or seminars to educate the site contractors and it was mentioned that the OSP is working on sample ordinances.
Mr. Dubay discussed Total Suspended Solids (TSS) removal desirable for tax base development and/or commercial development. TSS is salt and sand, removal is highly technical and it affects ground water recharge areas. Design tools require 2-foot depth to be adequate to receive soil, 2 feet above seasonal high water table and pre-treat before it goes into the ground. Detention systems under pavement optimize tax base development as opposed to open basins. Integrate sub-surface detention with roof recharge system.
To reduce TSS discharge you need 80% removal. Implement BMPs by serializing, paralleling and using a weighted average. Deep sump catch basins, treatment swales yield a 25% removal rate, ground water infiltration and hydrodynamic units yield an 80% removal rate. Hydrodynamic systems can be designed around natural features with bio retention areas (pockets of vegetation).
Ross McLeod motioned to adjourn. Ms. Prendergast seconded. Meeting adjourned 10:05 pm.
These minutes are in draft form and have not been submitted for approval.
Respectfully submitted, Lee Maloney
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