Buffers and Special Water Quality Protections

Carrie J. Evenson, Ph.D.Environmental Programs Specialist IV

Industrial Wastewater Enforcement Section

Water Quality DivisionDepartment of Environmental Quality

Jason R. Vogel, Ph.D., P.E.Assistant Professor

Extension Stormwater SpecialistBiosystems and Agricultural Engr.

Oklahoma State University

Special Water Quality Protections Outstanding Resource Waters (ORWs) Aquatic Resources of Concern (ARCs) Endangered/Threatened Species Impaired Waters

Buffer Requirements

Outline

Special Water Quality Protections

Outstanding Resource Waters (ORWs) Waters of the State designated in Oklahoma’s

Water Quality Standards, OAC 785:45, Appendix A

Include Illinois River & Lee Creek watersheds and Mountain Fork River watershed

Addendum F of OKR10 indicates locations

Outstanding Resource Water/Aquatic Resource of

Concern

Aquatic Resources of Concern (ARCs) Includes sections of the following:

Outstanding Resource Water/Aquatic Resource of

Concern

Grand (Neosho) River

Cimarron River South Canadian

River Muddy Boggy River Kiamichi River Little River

Glover River Mountain Fork River Spring River Illinois River Lee and Little Lee

Creeks Certain watersheds

Aquatic Resources of Concern (ARCs) Counties with no stormwater discharge-sensitive

endangered/threatened species:

Outstanding Resource Water/Aquatic Resource of

Concern

Alfalfa Beckham Carter Cimarron Comanche Garfield

Garvin Grant Greer Johnston Kiowa Lincoln

Murray Nowata Okfuskee Oklahoma Okmulgee Rogers

Stevens Texas Washita Washington

For sites discharging to ORW/ARC Indicate on NOI and address in SWP3

Inspection requirements Minimum of once every 7 days and within 24 hours of

a storm event of ≥0.5 inches or within 24 hours of snowmelt-related discharge

Outstanding Resource Water/Aquatic Resource of

Concern

For sites discharging to ORW/ARC Stabilization requirements

Initiated immediately following day earth-disturbing activities have temporarily or permanently ceased

Completed within 7 days

Corrective actions required

Outstanding Resource Water/Aquatic Resource of

Concern

For sites discharging to ORW/ARC 100 ft buffer zone required

Alternately, use Addendum I “Buffer Guidance” for equivalent controls

Temporary or permanent sediment basin required for areas that serve an area with ≥5 acres disturbed

Outstanding Resource Water/Aquatic Resource of

Concern

For sites discharging to ARC Discharge must be protective of listed

endangered/threatened species or designated critical habitat

Applicant must comply with requirements, conditions, terms identified as necessary to meet eligibility requirements

Outstanding Resource Water/Aquatic Resource of

Concern

Important Note:

Permit does not authorize discharges that cause a prohibited “take” or that are likely to jeopardize continued existence of species or habitat

Endangered/Threatened Species

Procedure for assessing potential effects of discharge on listed species (see Part 11): Complete prior to submitting NOI Step 1: Determine if project discharges to ARC

If project doesn’t discharge to ARC, no additional steps are necessary.

If project does discharge to ARC, proceed to Step 2.

Endangered/Threatened Species

Procedure for assessing potential effects of discharge on listed species (see Part 11): Step 2: Implement stormwater control

measures to protect listed species Retain sediment on site to the greatest extent

practicable Establish/retain 100 ft buffer zone or equivalent Follow stabilization requirements

Endangered/Threatened Species

Applicant must certify that it meets at least ONE of following criteria: Site is not located within any of the Aquatic

Resource of Concern (ARC) corridors; OR Site is located within ARC corridor and SWP3

describes area and measures used to protect species or habitat; OR

Endangered/Threatened Species

Applicant must certify that it meets at least ONE of following criteria (cont’d): Site is federally approved/authorized and

addresses Endangered Species act Section 7 consultation Must include documentation demonstrating

Section 7 consultation; OR Applicant’s discharge(s) is/are addressed in

another operator’s certification of eligibility

Endangered/Threatened Species

Applicant must certify that it meets at least ONE of following criteria (cont’d): If one of above can’t be met, may use Buffer

Guidance to select equivalent sediment controls or contact DEQ for guidance No longer necessary to contact USFWS for

guidance on alternatives

Endangered/Threatened Species

Identified by State or EPA pursuant to Section 303(d) of the Clean Water Act as not meeting applicable State water quality standards Includes

Waters with approved or established TMDLs, and Waters for which a TMDL has not yet been

established or approved

Impaired Waters

303(d) list and approved TMDLs/watershed plans can be found on DEQ website: For 303(d) list:

http://www.deq.state.ok.us/wqdnew/305b_303d/index.html

For approved TMDLs/watershed plans:http://www.deq.state.ok.us/wqdnew/tmdl/index.html

Impaired Waters

For sites discharging pollutants of concern to receiving water on 303(d) list: Document how BMPs will control discharge of

pollutants of concern If TMDL or watershed plan has been

approved Describe how SWP3 is consistent with

TMDL/watershed plan

Impaired Waters

For sites within one mile of streams impaired for sediment: Indicate on Notice of Intent Inspection requirements

Minimum of once every 7 days and within 24 hours of a storm event of ≥0.5 inches or within 24 hours of snowmelt-related discharge

Impaired Waters

For sites within one mile of streams impaired for sediment: Corrective actions

Document within 24 hours and implement within 7 days of discovery

Stabilization requirements Initiated immediately following day earth-

disturbing activities have temporarily or permanently ceased

Completed within 7 days

Impaired Waters

Buffer Requirements

Two (2) buffer requirements (see Addendum I) Alternative 1:

For sites discharging into receiving water located on or immediately adjacent to your site that are not an ARC or ORW Provide 50 feet of natural buffer as measured

from the top of the bank to disturbed portions of the site

Buffer Requirements

Two (2) buffer requirements (see Addendum I) Alternative 2:

For sites discharging to the watershed of ARC and/or ORW Provide 100 feet of vegetated buffer between

area disturbed and all perennial or intermittent streams; or 50 feet of vegetated buffer between area disturbed and all ephemeral streams or drainages.

Buffer Requirements

Retain and protect as much natural buffer from construction activities as possible Preexisting structures and impervious surfaces

are allowed in buffer provided vegetation outside preexisting disturbance is maintained

Buffer Requirements

Do not conduct earth-disturbing activities within buffer during permit coverage

Ensure all discharges are first treated by erosion and sediment controls before entering buffer

Buffer Requirements

Natural buffers and equivalent sediment controls don’t apply when: Water crossings, limited water access, and

stream restoration authorized under a Clean Water Act (CWA) Section 404 permit exist

No natural buffer exists due to preexisting development disturbances (e.g., structures, impervious surfaces)

Buffer Requirements

Three compliance alternatives Alternative 1: Provide and maintain a 50/100-

foot undisturbed natural buffer Alternative 2: Provide and maintain <50/100-

foot buffer and install additional erosion and sediment controls

Alternative 3: Implement equivalent erosion and sediment controls to achieve the same sediment load reduction as provided by a 50/100 foot natural buffer if natural buffer of any size is infeasible

Buffer Requirements

Buffer Requirements

Using Addendum I Step 1: Determine if buffer is required Step 2: Determine which compliance

alternative to use Step 3: If Alternative 1, measure existing

buffer width and retain and protect required natural buffer width Measured perpendicularly from the ordinary high

water mark or the edge of the stream or river bank, bluff or cliff For meandering waterbodies, you may measure in

regular intervals instead of measuring each change

Buffer Requirements

Step 4: If Alternative 2 or 3 selected: Document width and location of buffer in SWP3

(Alt. 2) Document why it is infeasible to provide and

maintain an undisturbed natural buffer of any size in the SWP3

Determine what additional controls must be implemented along with any retained natural buffer Addendum I lists process for determining which

BMP or combination of BMPs can provide equivalent sediment reduction as natural buffer

Determining equivalent sediment reduction Step 1: Estimate removal efficiency at site if

50/100 ft buffer could be provided Equivalent erosion and sediment controls must

provide sediment load reduction equivalent to this

Dependent on site-specific factors Includes precipitation, soil type, land cover, slope

length, width, steepness, and types of sediment controls used to reduce the discharge of sediment prior to the buffer

Buffer Requirements

Estimating removal efficiency of buffer Use buffer performance standards included in

Appendix I, Tables I-1 through I-4OR Conduct a site-specific calculation for sediment

removal efficiency Provide the specific removal efficiency and the

information used for the site-specific calculation in your SWP3

Buffer Requirements

Things to note when using Tables I-1 through I-4: Developed by Dr. Jason Vogel and Katie Beitz,

Biosystems and Agricultural Engineering, Oklahoma State University

Choose vegetation type that most closely matches vegetation that would exist naturally, regardless of condition No supplemental planting required Take credit as a fully vegetated “natural buffer” in

subsequent calculations

Buffer Requirements

Example: I am developing a commercial site in

Oklahoma City. How do I know if I need to have a buffer?

1. Take a look at how close the site is to the nearest surface water

Buffer Requirements

I’ve looked at my site, and it looks like I will need to clear ground within 50 feet of the stream in order to build my parking lot. Now what? Earth-disturbing activities will occur within 50

feet of surface water: Buffer is required Is surface water an ORW or ARC?

If NO – 50 ft buffer required If YES – 100 ft buffer required

Buffer Requirements

So I know I need to provide a 50 ft buffer. What’s next?1. Determine if you can provide the entire 50 feet

of undisturbed buffer on your site. If YES – protect buffer from earth-disturbing

activities for the duration of the project If NO – determine how much of a buffer can be

provided and what equivalent sediment control measures you will install instead Use Tables I-1 through I-4 for this

Buffer Requirements

I can’t maintain any buffer at my site. Now what do I do? Use Appendix I, Tables I-1 through I-4 to

determine sediment reduction provided by 50 feet of undisturbed natural buffer Site location: Oklahoma City Natural buffer vegetation: Weeds Site condition: Blade fill Soil type: Sand

Buffer Requirements

Example using Appendix I, Tables I-1 through I-4: Site location: Oklahoma City Natural buffer vegetation: Weeds Site condition: Blade fill Soil type: Sand Sediment removal efficiency based on Table I-

1: 41%

Buffer Requirements

I found the removal efficiency of a natural buffer at my site. How do I determine what sediment controls can provide an equivalent sediment load reduction? Select stormwater control(s) you want to use and

Use Table I-1 through I-4 to determine sediment load reduction OR

Use a model or other type of calculator showing how BMPs meet or exceed the sediment removal efficiency from Step 1

Buffer Requirements

If using Appendix I, Tables I-1 through I-4: Site location: Oklahoma City Natural buffer vegetation: Weeds Site condition: Blade fill Soil type: Sand Sediment removal efficiency of buffer based on

Table I-1: 41% Proposed sediment control measure: 12”

waddle

Buffer Requirements

Using Appendix I, Tables I-1 through I-4: Site location: Oklahoma City Natural buffer vegetation: Weeds Site condition: Blade fill Soil type: Sand Sediment removal efficiency of buffer based on

Table I-1: 41% Proposed sediment control measure: 12” waddle Equivalent sediment reduction of control measure:

90%

Buffer Requirements

Buffer Requirements

My selected sediment control provides adequate sediment load efficiency. Am I done yet? Document information from previous steps in SWP3

including: Buffer vegetation and soil type if Tables I-1 through I-4

are usedOR

Specific removal efficiency and other information for site-specific calculation

Stormwater control(s), model or calculator used (other than Tables), and results of calculations

So what if I don’t want to use Tables I-1 through I-4? Use other available calculation methods or

models

Buffer Requirements

Alternative Calculation Methods

Alternative Calculation Methods

Model options for calculating effectiveness of alternative controls RUSLE-series programs (USDA) WEPP (USDA) SEDIMOT series (downloadable, developed by

Barfield et al.) SedPro (Woolpert, Inc.) SEDCAD (Civil Software Design, LLC)

RUSLE – Revised Universal Soil Loss Equation

A = (R)(K)(LS)(C)(P)

A=Erosion per unit areaK=Soil Erodibility

LS=Land slope and lengthC=degree of soil coverSupporting practices

Erosivity - R

Las Vegas, NV 8Phoenix, AZ 22Denver, CO 40Syracuse, NY 80Minneapolis, MN 110Chicago, IL 140

Measure of erosivity of climate at a location

Richmond, VA 200St. Louis, MO 210Tulsa, OK 260Dallas, TX 275Birmingham, AL 350Charleston, SC 400New Orleans, LA 700

SOIL ERODIBILITY - K

Effect of texture clay (0.1 - 0.2) resistant to detachment sand (0.05 - 0.15) easily detached, low

runoff, large, dense particles not easily transported

silt loam (0.25 - 0.35) moderately detachable, moderate to high runoff

silt (0.4 -0.6) easily detached, high runoff, small, easily transported sediment

LS Factor – Length Slope

Describes Topography Overland flow slope length Slope lengths for eroding portions of

hillslopes Steepness Hillslope shape

Slope Length for Eroding Portion of Slope

Only works for simple slopes Traditional definition

Distance from origin of overland flow to concentrated flow or to where deposition begins

Definition is flawed for strips and concave:convex slopes

Best approach: Use overland flow slope length and examine RUSLE2 slope segment soil loss values

Detachment Proportional to Slope Steepness Factor (S)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 5 10 15 20 25 30 35

Slope Steepness (%)

Fa

cto

r V

alu

eNot affected by any other variable

C & P Factors – Based on Land Use

C: Cover-management

P: Supporting practices

Cover-Management

Vegetative community Crop Crop rotation Conservation tillage Application of surface and buried materials

(mulch, manure) Increasing random roughness

Supporting Practices

Erosion control (called permeable barriers) Silt fence, waddles, check dams

Contouring Strip systems

Buffer, filter, strip cropping, barriers Terrace/Diversion Impoundments

Example

Changing the Average

Steepness and Length of Slope

Choosing the Location

Example: Tulsa, OK

Choosing the Soil of the Site

Example: Silt Loam

Choosing the Management of

the Surface

Example: the first 50 feet are

blade cut

Choosing the Management of

the Surface

Example: we added a silt fence at 50

feet, and added a barrier strip for the second 50’ of the area

Adding a Wattle

Example: 6” Wattle

In this screen you can also set

the spacing, and number of wattles used

Estimate Sediment Removal

Soil Loss - Sediment DeliverySoil Loss

Example: 39-2.5/39 = 94%

Questions, Comments, Discussion