Update to Delaware Sediment & Stormwater Regulations
Post on 25-Nov-2021
3 Views
Preview:
Transcript
C T A C M E E T I N G
N O V E M B E R 8 , 2 0 1 7
Update to Delaware Sediment & Stormwater Regulations
Randy Greer, PEDNREC Sediment & Stormwater Program
Sediment & Stormwater Program
Employs a comprehensive approach to sediment control (both during and after construction) and stormwatermanagement that includes monitoring of stormwaterquantity and water quality control. Program responsibilities include:
Sediment control and inspection during construction
Post-construction inspection of permanent stormwaterfacilities
Stormwater quantity and water quality control
Education/training relating to stormwater
Sediment & Stormwater Program
Original Sediment and Stormwater Regulations adopted in 1990
In response to Executive Order 62 signed into effect by Gov. Minor, a Task Force on Surface Water Management was established and findings published in 2005
As a result, regulations were developed and issued in 2013 with a final adoption in 2014
Guiding Principals that changed 1990 vs 2013/14: Peak-based to Volume-based management
Site-level to Watershed-level management
Separated regulatory language from technical requirements
Streamlined plan review/approval process
Sediment & Stormwater Program
Regulations = WHAT Regulatory Authority
Applicability
Compliance Details
Technical Document = HOW Information that supports regulations
Background information
Procedures
Checklists
Standards & Specifications
Examples
Sediment & Stormwater Regulation Revisions
Where are we now?
October 2015 – Delaware Superior Court invalidated the 2013/2014 version of the Delaware Sediment and Stormwater Regulations on procedural grounds
April 2016 – Delaware Supreme Court upheld the Superior Court’s decision
April 2016 – DNREC adopts interim emergency sediment and stormwater regulations
June 2016 – Gov. Markel signs SB 253 into law authorizing DNREC to provide additional flexibility in meeting standards for sediment and stormwaterregulations
Sediment & Stormwater Regulation Revisions
Senate Bill 253 – Changes to the Law:
E&S only for residential land disturbing activity less than one acre.
Ag Structures (including poultry houses) disturbing 10 acres or less qualify for Standard Plans.
Stormwater discharges for the 10-YR and 100-YR storm events not required to manage runoff volume.
Allows alternative method to calculate the RPv volume based on 1” of runoff.
Allows applicants to use the provisions under SB 253 or continue under the 2016 Emergency Regulations.
Allows applicants to use additional BMPs that are functionally equivalent.
Extends the approval period for plans from 3 years to 5 years.
Extends the re-delegation period from 3 years to 5 years.
This compromise allows additional time for the RAC to thoroughly discuss all of the necessary amendments to the Sediment and Stormwater Regulations by eliminating the 180 day expiration of the Emergency Regulations.
Sediment & Stormwater Program
Regulatory Advisory Committee – RAC
Name AffiliationAdams, Chuck Delaware Assn of SurveyorsBross, Jeff Water Infrastructure Advisory CouncilCasey, John Delaware Contractors' AssnClark, Jeff Board of Landscape ArchitectureDurstein, Dirk Dept. of JusticeGilliam, LaTonya DelDOTHokuf, Doug New Castle CountyHolland, Connie Office of State Planning CoordinationHorsey, Bobby David G. Horsey & SonsJones, Bruce ACEC ‐ DEKea, Frank Secretary Designee ‐ Land Development ConsultantKeifer, Sarah Kent CountyKillmer, Lew League of Local GovernmentsMcGinnis, Phil Delaware Association of RealtorsMedlarz, Hans Sussex CountyMorrill, Paul Committee of 100Palmer, Bob DNREC Secretary's OfficeRiemann, Michael Homebuilders Assn of DelawareSchell, Preston Secretary Designee ‐ Land DeveloperTravers, Kristen Delaware Nature SocietyWatson, Jessica Delaware Assn of Conservation Districts
Sediment & Stormwater Regulation Revisions
What’s Next?
Technical Subcommittee Meetings are scheduled to tackle the details: Standards Plans – 1 Acre Lots and Ag (Poultry) Operation
New RPv Volume – 1” of runoff
Regulations
Technical Standards
Offsets
Redevelopment
Sediment & Stormwater Regulation Revisions
What are the Source Water Protection Issues Related to Urban Stormwater Runoff?
Sediment & Stormwater Regulation Revisions
EPA NURP (c. 1970s)
First EPA funded research on water quality of stormwater runoff
28 metropolitan locations
Metals and nutrients major threats
Generally focused on surface water impacts
Two project sites located over sole source aquifers did not appear imminently threatened, but more research recommended
Sediment & Stormwater Regulation Revisions
National StormwaterBMP Database (2001)
International Stormwater Quality Database (since 2004)
Over 600 BMP studies All 50 states + 4
countries Consistent with NURP
results, except for Pb Also focused on surface
water impacts (influent vs. effluent)
Sediment & Stormwater Regulation Revisions
Sediment & Stormwater Regulation Revisions
Drinking Water Stds
(MCLs)
Cu: 1.3 mg/L (P)
Pb: 0.015 mg/L (P)
Zn: 5 mg/L (S)
NO2: 1 mg/L (P)
NO3: 10 mg/L (P)
Constituents listed in National Drinking Water Regulations
Sediment & Stormwater Regulation Revisions
What are the Source Water Protection Issues?
Potential GW contaminants in stormwater runoff Nutrients
Metals
Chlorides?
National Secondary Drinking Water Regulations: 250 mg/L
Sediment & Stormwater Regulation Revisions
Sediment & Stormwater Regulation Revisions
Sediment & Stormwater Regulation Revisions
Sediment & Stormwater Regulation Revisions
Sediment & Stormwater Regulation Revisions
What are some best practices for managing chloride deicers?
Covered storage
Calibrated application equipment
Pre-treatment
Alternative deicing compounds Beet juice derivatives
Calcium magnesium acetate (CMA)
Sediment & Stormwater Regulation Revisions
What other measures do the DSSR contain to protect Source Water?
Sediment & Stormwater Regulation Revisions
Sediment & Stormwater Regulation Revisions
What measures do the DSSR contain to protect Source Water?
Pretreatment required for all infiltrating practices Vegetative filtration
Forebays
Pre-engineered practices
Vertical separation from SHGW Minimum 2’
Horizontal setback distances between wells and stormwater BMPs
Sediment & Stormwater Regulation Revisions
GW Discharge BMPs Surface Water Discharge BMPs
Land Use Domestic Public Domestic Public
Residential Commercial Institutional 50 75 10 10
Highway 100 150 50 75
Hotspot (gas station, etc.) Contaminated/Brownfield NPDES Permitted Industrial 100* 150* ** **
NOTE: Setback distances measured from 10-YR WSEL
*Generally discouraged but may be permissable with enhanced pre-treatment
** Maximize and evaluate on case-by-case basis
Sediment & Stormwater Regulation Revisions
Sediment & Stormwater Regulation Revisions
Take-Aways:
Most constituents found in urban stormwater runoff do not pose inordinate risk to source waters
The current and proposed DSSR follow EPA guidelines for protection of source waters
Properly designed infiltrating stormwater BMPs minimize potential impacts to source waters
Chlorides have greatest potential to negatively impact source waters, but data is lacking on the magnitude of the problem In meantime, chlorides best managed through source controls
Questions?
Randy Greer, PE
State of Delaware - DNREC
Division of Watershed Stewardship
Sediment & Stormwater Program
89 Kings Highway
Dover, DE 19901
Ph: 302-739-9921
randell.greer@state.de.us
top related