ashe meeting on ms4, swm, nutrient credits, drainage

Pawan Sarang, P.E.District Drainage EngineerNorthern Virginia District

April 19, 2016

ASHE Meeting on MS4, SWM, Nutrient Credits, Drainage

STORMWATER RUNOFF*

Rain and snowmelt create stormwater runoff because not all stormwater “percolates” into the ground

Stormwater runs over the ground and eventually enters waterbodies (i.e. streams, rivers, or lakes)

* From VDOT-CO MS4 Presentation2

TRANSPORT OF POLLUTANTS*

A pollutant is a material or chemical that affects water quality of a receiving waterbody

Pollutants are transported during a storm event, and the pollutants are washed off with the stormwater

Pollutants that are in the stormwater are then discharged into waterbodies (lake, river, stream, creek, etc.)

* From VDOT-CO MS4 Presentation

3

OVERVIEW OF VDOT’S MS4 PROGRAM

Municipal Separate Storm Sewer System (MS4)

www.virginiadot.org/programs/stormwater_management.asp

4

General VPDES Permit for Discharges of Stormwater from MS4 (VAR040115)Coverage from November 01, 2013 to June 30, 2018The link beside other things includes MS4 Progress Reports that VDOT provides to VA DEQ.

OVERVIEW OF VDOT’S MS4 PROGRAM

• Authorities involved with MS4• US Environmental Protection Agency

(EPA)• Given federal authority through the Clean

Water Act• Compliance and enforcement authority

• Virginia Department of Environmental Quality (DEQ)

• Given statewide authority by EPA• Compliance and enforcement authority• Issue permits

• Individual Permits• General Permits (5-year cycle)

5

OVERVIEW OF VDOT’S Municipal Separate Storm Sewer System (MS4) Program

VDOT is a MS4 Permit Holder and executes Annual Agreement for its Standards and Specifications with VA DEQ which includes SWM Program and Erosion and Sediment Control Program.

VA DEQ reserves the right to randomly select projects for review (in either the design or construction phase) to ensure compliance with the VDOT approved Program.

VDOT Roles and Responsibilities • Central office staff will develop MS4 program wide policies and

procedures, handle annual reporting, training, and assessment of VDOT’s operations

• District staff will be responsible for implementation of various components of the program within the regulated area

VDOT projects are designed in accordance with the VDOT Erosion and Sediment Control and Stormwater Management Program Specifications Manual (24VAC30-91-160), the Erosion and Sediment Control Regulations, 9VAC25-840, and the Virginia Stormwater Management Program (VSMP) Regulation, 9VAC25-870.

6

MS4 Program – Six Minimum Control Measures (MCM)

Public education and outreach on stormwater

impacts(MCM 1)

Public involvement/participation

(MCM 2)

Illicit discharge detection and elimination

(MCM 3)

Construction site stormwater runoff control

(MCM 4)

Post-construction stormwater management in new development and

redevelopment(MCM 5)

Pollution prevention/good housekeeping for

operations(MCM 6)

Duties of District MS4 Coordinator

Duties include, but are not limited to: • implementing and coordinating the MS4 Program districtwide • performing compliance inspections at construction projects and maintenance facilities MS4 areas versus non-MS4 areas • developing corrective actions based on compliance inspections; • assisting with public outreach and VDOT training • giving technical/compliance advice • participating in local watershed planning meetings • assisting with investigation of illicit discharge reports • coordinating with TMDL staff to develop, prepare, and recommend TMDL Action Plans • preparing and submitting of annual report information to Central Office Coordinate with, but not limited to: • Various VDOT Divisions (Environmental, Maintenance, Construction, Residency staff,

etc.), • Other MS4 Authorities (infrastructure coordination, illicit discharge elimination) • Regulatory Agencies (DEQ construction inspections); and • the general public

9

TIMELINE EVENTS FROM EPA AUDITEvent* Date

EPA officially notified VDOT by email 10/10/12

Conference Call with EPA to discuss audit process 10/19/12

EPA performed field visits of construction and maintenance 10/22/12 –10/25/12

EPA debriefed VDOT at Central Office 10/26/12

VDOT provided additional documentation at EPA’s request 11/30/12

VDOT received EPA Inspection Report (March 2014) 3/26/14

Conference Call with EPA to discuss observations in Report 5/8/14

VDOT response to EPA on Illicit Discharge Detection Elimination 8/1/14

Finalize AOC and CAFO 6/30/15

Finalize CIP 12/1/15

Note: *VDOT and EPA have had various email correspondence throughout this process

10

MAIN ISSUES NOTED IN EPA REPORT

CONSTRUCTION• Unstabilized areas

• Denuded areas not protected with matting, seeding or other stabilization• Outfall areas not protected with riprap or other erosion measures

• Inadequacies with maintenance of ESC measures• Silt fence was sipped or installed incorrectly • Drop inlet protection was overtopped

• Inconsistencies with inspection frequency• Inspections were not performed within 14 day timeframe from Spec Book

• Inadequacies with corrective action in required timeframes• Subsequent reports were noting deficiencies still present

• Chemical Storage and Good HousekeepingVisual evidence of petroleum staining and sediment migrationChemicals containers exposed to precipitation

• Lack of documentation for corrective actions• Follow-up reports and diaries were incomplete

11

MAIN ISSUES NOTED IN EPA REPORT

MAINTENANCE FACILITIES

• Inadequacies in good housekeeping and pollution prevention• Deficiencies in material management• Spill prevention and response

• Current level of stormwater-related training efforts• EPA questioned whether specific pollution-prevention training was being

performed at statewide level• Was training effective or understood by field personnel/implementing?

• Current level of site specific procedures for facilities• EPA questioned whether a Stormwater Pollution Prevention Plan existed• Did the facility understand what procedures applied to their daily activities?

• Lack of documentation for corrective actions• Follow-up reports and diaries were incomplete

12

VSMP Construction Permit (from July 1, 2014 to June 30, 2019)Coverage under this permit is required for all land disturbing activities (except those associated with routine maintenance) that equal or exceed the following land disturbance threshold amounts:

All areas inside or outside CBPA – 1 Acre or greater

Storm Water Pollution Prevention Plan (SWPPP) Section 107.16 (e) of the 2007 VDOT R&B Specifications requires all land disturbance activities that disturb 10,000 square feet or greater (2500 square feet or greater in the area defined as Tidewater, Virginia in the Chesapeake Bay Preservation Act) to have a SWPPP including appropriate Erosion and Sediment Control Measures (IIM-LD-11 – latest version ) .

SWPPP General Information Sheets Make sure to include sheets in Plan Assembly (IIM-LD-246 – latest version). These sheets are preamble to all VDOT requirements that have been specifically met for a particular project. These sheets include general information on land disturbance, Erosion and Sediment Control Plans, Notes etc. and Post Construction SWM Plan for a particular project.

13

SWM RequirementsSWM Requirements are applicable for those regulated land disturbance activities (RLDA) that disturb one acre or greater except in those areas designated as a Chesapeake Bay Preservation Area in which case the land disturbance threshold is 2500 square feet or greater.

Routine maintenance is those activities that are performed to maintain the original line and grade, hydraulic capacity of the original construction of the project.

14

SWM RequirementsPer IIM-195.8 dated July 15, 2014:

Definition of Site (“Applicable Area”) – The area of proposed land disturbance (e.g., the construction limits) plus any right of way acquired in support of the proposed land disturbance activity/project. Any support areas within existing or proposed VDOT right of way associated with the proposed land disturbance activity/project and identified in the pre-construction SWPPP for the proposed land disturbance activity/project shall also be considered a part of the site. Permanent easements and/or other property acquired through the right of way acquisition process in conjunction with the proposed land disturbance activity/project may be considered a part of the site and utilized in the determination of the post-development water quality requirements provided such property will remain under the ownership/control of the VDOT and providing such property is so identified/designated on the proposed land disturbance activity/project plans and is legally encumbered for the purpose of stormwater management.

15

SWM RequirementsPer upcoming IIM-195.9 dated TBD:

Routine maintenance is defined as those activities performed to maintain the original line and grade, hydraulic capacity, or original construction of the facility. Such activities include, but are not limited to, ditch cleaning operations, shoulder grading operations, pipe replacement or rehabilitation operations, pavement milling and/or overlays (see additional discussion in this section), bridge deck replacement, and the normal operational procedures for maintaining the travel surface of unpaved/gravel roadways (i.e., dragging, blading, grading, etc.). When classifying a land disturbance activity as a routine maintenance, consideration should be given to the fact that changes to the size, shape, slope and material of a drainage feature (i.e., ditch, culvert, etc.) may alter the conveyance of flow, but may still maintain the original hydraulic capacity of the facility, since, for certain flood events, that may include conveyance of flow over the roadway section.

16


The paving of an existing road with a compacted or otherwise impervious surface (e.g., gravel) and re-establishment of original ditches and shoulders is considered routine maintenance for the purposes of determining the applicability of the VSMP Regulations provided all of the following conditions are met:

1. The proposed paved area will approximate the existing compacted or otherwise impervious area.

2. There will be no changes to the existing horizontal or vertical alignment.3. Roadside ditch work will only be performed as necessary to re-establish

original line, grade or hydraulic capacity, provide positive drainage or address safety concerns.

4. Drainage pipe work will only be performed as necessary to extend existing structures, replace structurally deficient structures or address safety concerns.

Facilities that support the routine maintenance activity (e.g., disposal areas for surplus dirt or borrow pits) are not considered a part of the routine maintenance operation and, therefore, are not covered under the routine maintenance activity exemption.

17


Milling and/or overlaying or other such rehabilitation or the removal and replacement of an existing traveled way pavement structure within the same footprint is not considered a land disturbing activity provided such operations do not expose the subgrade (i.e., the earth below the subbase/base aggregate material). The area of the existing pavement meeting this criterion would not be included with the other land disturbance areas of the project for the purposes of determining the applicability of the ESC Law and Regulations, the VSMP Regulations and the VPDES General Construction Permit. Any shoulder or ditch grading associated with the rehabilitation or replacement of the existing traveled way pavement structure would be considered in the calculation of the total land disturbance quantity for the proposed activity. Exception - Shoulder or ditch grading associated with a routine maintenance operation would not be included in the calculation of the total land disturbance quantity for the purposes of determining the applicability of the VSMP Regulations and the VPDES General Construction Permit

18


Where a project contains the milling and/or overlaying or replacement of an existing traveled way pavement structure within the same footprint in conjunction with other improvements (e.g., adding additional lanes to a roadway facility), the milling and/or overlaying or the removal and replacement of the existing travel way pavement structure within the same footprint can be considered as routine maintenance and not included as a part of the regulated site for the purposes of defining compliance with the VSMP Regulations provided that:

1. The milling and/or overlaying or the removal and replacement of the existing traveled way pavement structure complies with the requirements of this Section and,

2. The milling and/or overlaying or the removal and replacement of the existing traveled way pavement structure could be accomplished as a distinct and separate operation, and,

3. The milling and/or overlaying or the removal and replacement of the existing traveled way pavement structure is, for the most part, continuous throughout the project limits.

19


For any maintenance activity being classified as routine, the activity files shall be documented regarding the original and proposed line, grade, hydraulic capacity and construction of the facility. Documentation of original conditions can be in the form of old plans, photographs or other such documents depicting the original line and grade, hydraulic capacity, or original construction of the facility. Written and signed statements from those that know the history of the facility can also serve as documentation of the original conditions.

Where there is any question as to the application of the routine maintenance definition to a land disturbing activity, the appropriate District Hydraulics Engineer should be consulted.

20

21

BMP Selection Table 1 of IIM-195.8

* See the Virginia SWM Handbook for approved systems. Other systems meeting the definition of a hydrodynamic or filtering structure must be approved by the DEQ prior to use.** See Technical Bulletin No.6 in the Virginia SWM Handbook.

TABLE 1BMP SELECTION TABLE

Water Quality BMP Target Phosphorus RemovalEfficiency

Applicable Percent ImperviousCover of Site

Vegetated filter stripGrassed swale

10%15% 16-21%

Constructed wetlandsExtended detention (2xWQV)Retention basin I (3xWQV)

30%35%40%

22-37%

Bioretention basinBioretention filterExtended detention-enhancedRetention basin II (4xWQV)Infiltration (1xWQV)

50%50%50%50%50%

38-66%

Sand filterInfiltratration (2xWQV)Retention basin III (4xWQV withaquatic bench)

65%65%65% 67-100%

Manufactured BMP Systems

Hydrodynamic Structures * 20%

Manufactured BMP Systems

Filtering Structures * 50%

FilterraTM Biorention Filter System ** 74%

SWM RequirementsPer IIM-195.8:Section 5.4.7: Alternative BMPs

Section 5.4.7.1:BMPs included on the Virginia SWM BMP Clearing House website may be used with the Performance Based water quality criteria. When doing so, the maximum removal efficiency allowed will be that shown for phosphorus removal by treatment. Any removal efficiency associated with phosphorus removal by run-off reduction will not be allowed.

Section 5.4.7.2: Other alternative BMPs not included in Table 1 or the Virginia SWM BMP Clearing House website may be allowed at the discretion and approval of the DEQ.

Section 5.4.7.3: Approval to use alternative BMPs is to be coordinated between the VDOT District or Central Office SWM Plan Designer and the DEQ Regional Stormwater Manager. The VDOT State Stormwater Management Program Administrator and the DEQ Central Office Director of the Office of Water Permits shall be copied on any correspondence related to a request for approval of the use of any alternative BMPs.

Section 5.4.8: Use of LID and BSD practices are encouraged to the maximum extent practicable in order to reduce the

stormwater runoff impacts of proposed development. LID practices include, but are not limited to, the preservation/protection of riparian buffers, wetlands, steep slopes, mature trees, flood plains, woodlands and highly permeable soils. BSD practices include, but are not limited to, reduction of impervious cover, conservation of natural areas and the more effective use of pervious areas to treat stormwater runoff.

22

23

Retention Basins

24

Enhanced Extended Detention Basins

25

Grass & Water Quality Swale

26

Bioretention Facilities

27

Underground BMPs (Innovative)

28


Tree Box Filter inVDOT Maintenance Area Headquarters

29


30


Storm Filter BMP on Old Bridge Rd projectStorm Filter

31


Washington D.C. Underground Vault Sand Filter(Virginia Stormwater Management Handbook, 1999, Et seq.)

Route 611 – Telegraph Road – Sand Filter with Pre-Treatment by StormCeptor

32

Underground BMPs (Maintenance)

33

SWM Construction& Maintenance Issues

34


35


As-Built Certifications

As-Built Certification of Stormwater Management Facilities (BMPs):

The Contractor shall provide ‘As-Built’ drawings of all stormwater management facilities. The ‘As-Built’ drawings shall show the actual finished ground contours, outlet structure dimensions and elevations, etc as they exist at the completion of the project. These drawings shall be signed and sealed by the Professional Engineer or Land Surveyor registered in the State of Virginia. All costs shall be included under Construction Surveying.

“The Contractor shall provide certification from an independent source that all proposed BMP facilities were constructed in accordance with applicable and current industry standards, and the manufacturer’s specifications. All costs shall be included under Construction Surveying.”

“The contractor shall be responsible for maintaining the proposed BMP once all connections have been accomplished, and shall certify that the BMP has been maintained per industry standards prior to transfer to VDOT.”

36

37

VDOT – Stormwater Management -

Nutrient Credits

38

SWM Nutrient Credits

Nutrient Credits purchase is good when using both Part II B (Runoff Reduction Method) as well as Part II C (Performance Based Approach) for water quality component. Purchase of Nutrient Credits does not address water quantity component for Part II B (Energy Balance Approach) or Part II C (Minimum Standard 19 (MS-19)). Other SWM BMPs (available from toolbox in DEQ website for BMP Clearing House) would be needed to address water quantity control requirements.

It is important to note that the purchase of nutrient credits cannot be used to address water quantity control requirements.

39


The purchase of nutrient credits to address post-construction water quality reduction requirements for construction activities are outlined in IIM-251.2 (latest version).

Moreover, it is also stated that the purchase of nutrient credits shall be considered the preferred alternative when available and economically feasible.

The VDOT State Stormwater Management Program Administrator will determine the availability of nutrient credits for use in satisfying the water quality requirements for the project and will notify the Project Manager of their determination. Where nutrient credits are available, the VDOT State Stormwater Management Program Administrator will secure from the Project Manager a project charge code for the purchase. The VDOT State Stormwater Management Program Administrator will then begin the process of securing the necessary nutrient credits. Once the procurement process is completed, the Project Manager and the District Hydraulics Engineer will be notified of the name of the Bank from which the nutrient credits were purchased so that it can be included with other required information in the appropriate sections of the SWPPP General Information Sheets associated with the land disturbing activity.

40


In order for the project to qualify for the use of nutrient credits, the project must meet one of the following criteria: 1. The project area contains less than 5-acres of land disturbance, or 2. The post-construction phosphorus reduction requirement is less than 10 pounds per year, or 3. Where the project does not meet the conditions noted in items 1 and 2, and at least 75% of the required phosphorus load reduction can be met onsite, the remaining load reduction (up to 25%) may be met through the purchase of nutrient credits.

So, if the project disturbs less than 5 acres and needs less than 10 lbs./year of phosphorus, then 100% of those lbs. for phosphorus can be purchased as nutrient credits. Currently, CO-L&D purchases these for project (upon request) from District (Use of LD-453 form). The money is taken from the UPC of that project.

If you purchase a large amount of Nutrient Credits for a specific project and all the Nutrient Credits are not utilized, the balance can be applied to other projects as discussed in 9VAC25-870-69 of the regulations.

41


VDOT is required to submit an annual report to the DEQ that identifies the nutrient credits purchased during the reporting year. The reporting period is from July 1st to June 30th.

When the purchase of nutrient credits is being used to satisfy the water quality requirements for a project, the Project Manager with the assistance of the District Hydraulics Engineer shall identify such on the LD-445 form when registering for coverage under the VPDES Construction Permit. The use of nutrient credits is to be documented in the appropriate section of the SWPPP General Information Sheets associated with the land disturbing activity.

Upon completion of the project, the appropriate information regarding the purchase of nutrient credits shall be reported on the LD-445D form for termination of VPDES Construction Permit coverage.

42


43

SWM Nutrient Credits – Form LD-453

Date:

From:

To:

Project Number:

District: Residency:

Project Location (City/County):

Latitude: Longitude:

UPC Number: Activity Code :

Project 4th order 8 digit HUC:

Click here for link to map

Amount of Nutrient Credits needed to be purchased (pounds/year):

*(Not to exceed 10 pounds per year without additional documentation )

Land Disturbance Area (Acres) : *(Not to exceed 5 acres without additional documentation)

VIRGINIA DEPARTMENT OF TRANSPORTATIONLOCATION AND DESIGN

NUTRIENT CREDIT PURCHASE FORM

44


The Chesapeake Bay Watershed Nutrient Credit Exchange Program (Code§ 62.1-44.19:14 et seq.) and the Stormwater Nonpoint Nutrient Offset legislation (Code§ 10.1-603.8:1) allow regulated land disturbance activities to utilize offsite options to achieve post development water quality criteria. This includes, under certain circumstances, the purchase of nutrient credits. Nutrient credits are generated by Nutrient Credit Banks through the construction of BMPs, or more typically, through land use conversion (e.g. converting crop land to forest). Nutrient Credit Banks are certified by the SWCB and regulated by the DEQ.


Wetland Banking Stream Banking

Source: CBNLT-Casey


Source: CBNLT-Casey

47

SWM Nutrient CreditsBefore After

Source: CBNLT-Casey

48


Source: CBNLT-Casey

49


Source: CBNLT-CaseyWildwood Farm

Chapter 6 VDOT Drainage Manual (Hydrology)

Section 6.2.9 talks about Approved Peak Discharge Methods.

Section 6.2.10: Design Frequency: design frequency should be selected commensurate with the facility cost, amount of traffic, potential flood hazard to property, expected level of service, political considerations, and budgetary constraints as well as the magnitude and risk associated with damages from larger flood events. When long highway routes that have no practical detour are subject to independent flood events, it may be necessary to increase the design frequency at each site to avoid frequent route interruptions from floods. In selecting a design frequency, potential upstream land uses should be considered which could reasonably occur over the anticipated life of the drainage facility.

50

Roadway Classification ExceedenceProbability Return Period

Rural Principal Arterial System 2% 50-yr

Rural Minor Arterial System 4% - 2% 25 yr - 50-yr

Rural Collector System, Major 4% 25-yr

Rural Collector System, Minor 10% 10-yr

Rural System 10% 10-yr

Urban Principal Arterial System 4% - 2% 25 yr - 50-yr

Urban System 4% 25-yr



51

Section 6.2.10: Design Frequency

Note: Federal law requires interstate highways to be provided with protection from the 2% flood. Facilities such as underpasses and depressed roadways, where no overflow relief is available, should also be designed for the 2% event.

Chapters within VDOT Drainage Manual that deals with hydraulic design

Chapter 3 relates to Documentation/Reports for various stages of plan development. Section 3.3.3 is going to change to reflect various milestone for project delivery.

Chapter 7 deals with design of ditches and channels – mostly uses open channel hydraulics. There is discussion on minor and major channel as well. Shear stress criteria for ditch design is upcoming as well.

Chapter 8 deals with culvert design – design storm based upon roadway classifications. Softwares such as HY-8, HECRAS etc. are listed for use.

Chapter 9 deals with design of Inlets, Storm Sewers, HGL etc. – generally spread at inlet, design frequency of closed storm drainage system (such as pipes) is discussed.

Chapter 10 deals with Erosion and Sediment Control measures and design.Chapter 11 deals with SWM designChapter 12 deals with Bridge, Structure and Riverine Hydraulics – use of

HECRAS and floodplain management is discussed.

52

Reference Documents for VDOT relative to ESC, SWM & VPDES (Design, Construction & Maintenance)

2007 Road and Bridge (R&B) Specifications (also include any supplemental sections). 2008 Road and Bridge (R&B) Standards and its latest updated version. VDOT Drainage Manual - Adopted April 2002 (latest version in January 2016) BMP Design Manual (2013) Stormwater BMP Standards & Specifications (2015) Informational and Instructional Memorandums:

IIM-LD-11.28 (for Erosion and Sediment Control) IIM-LD-110.24 (General Notes) IIM-LD-195.8 (for Storm water Management Requirements) IIM-LD-233 (for Natural Channel Design) IIM-LD-242.5 (for VPDES Construction Permit) IIM-LD-246.3 (for Stormwater Pollution Prevention Plan (SWPPP)) IIM-LD-251.2 (Nutrient Credits)

Locally Administered Projects Manual 2011 Secondary Street Acceptance Requirements Design Build Manual Other manuals (for Design, Construction and Maintenance) which can be checked in at:

http://www.virginiadot.org/business/manuals-default.asp

53

54

QUESTIONS ?