regulatory setbacksregulatory setbacks and buffersand

Regulatory SetbacksRegulatory Setbacks and Buffersand Buffers

RIDEM OWTSRIDEM – OWTS

Brian MooreBrian MooreSupervising Sanitary Engineer

RIDEM O it PRIDEM Onsite Program

Definitions - Watercoursepond

Any of the following:

marsh stream

brook river

stream

lake wet meadow

swamp

bog other standing body of water

fen Including any affected by tidal waters

Definitions – Subsurface DrainDefinitions Subsurface Drain

Any system of below surface piping orAny system of below surface piping or highly permeable material intended to lower the groundwater table of an arealower the groundwater table of an area, and which has an outlet to the surface for the collected groundwaterthe collected groundwater.

e.g.: Foundation drain, french drains.

Definitions – Storm DrainDefinitions Storm Drain

Any pipe or structure design to collect carryAny pipe or structure design to collect, carry and/or divert surface runoff.

Definitions – TributaryDefinitions TributaryFlowing body of water or watercourse that

provides intermittent or perennial flow to down-gradient watercourses that eventually discharge to the waters of concern (e.g., reservoir impoundment or salt pond).

Definitions – Tributary WetlandDefinitions Tributary WetlandFreshwater wetlands within a watershed thatFreshwater wetlands within a watershed that

are connected via a watercourse to the waters of concern (e.g., drinking waterwaters of concern (e.g., drinking water supply impoundment or coastal wetland or tidal waters).t da ate s)

Definitions – Wellhead Protection AreaArea as designated by the Director in the DEM

“Rules and Regulations for GroundwaterRules and Regulations for Groundwater Quality” surrounding a public well or wellfield through which water will move toward andthrough which water will move toward and reach such well or wellfield.

Definitions – Bedrock and Rotten Rock

Bedrock: Rock, commonly called ledge, that f th th’ t B d k i l dforms the earth’s crust. Bedrock includes rotten rock.

Rotten Rock: Any decomposed but still y pcoherent rock. Rotten Rock is greater than 50% coherent rock and lies above equal or qmore coherent rock.

Definitions – Restrictive LayerDefinitions Restrictive Layer

A soil horizon that is assigned to a soil t 10 d fi d i R l 15 11category 10 as defined in Rule 15.11.

Table 22.1- Page 46

Table 22.1- Page 46

Note 1: Distance may be reduced when yseamless sleeves are used.

Table 22.1- Page 46

Note 2: Not applicable to building sewer and septic tank effluent pipeseptic tank effluent pipe.

Note 3: Any single leachfield designed to y g gtreat more than two thousand (2000) but less than five thousand (5000) gallons per day.

Note 4: As defined in Rule 35.1.1.

Table 22.1- Page 46

Note 5: Distance shown is the minimum for upgradient and side gradient directions. Downgradient separation distance will be based on nitrate modeling and shall be a minimumon nitrate modeling… and shall be a minimum of 50 feet.

Table 22.1- Page 46

Note 6: 15 feet if no foundation drain. 8 feet with slab or when basement floor elevation is higher than building sewer.

Table 22.1- Page 46

N t 7 Di t b d d hNote 7: Distance may be reduced when seamless sleeves are used.

Table 22.1- Page 46

Note 8: If the slope is <3% over leachfield and 50’ perimeter then setback is 50’ in alland 50 perimeter, then setback is 50 in all directions unless GW flow study shows drain is upgradient.pg

Note 9: If drain is watertight, bedded in sand or bank run gravel; above the SHGWT; then setback may be 25’.

Table 22.1- Page 46

Table 22.1- Page 46

Note 10: On residential property with both an OWTS and a stormwater infiltration system, the distance between an OWTS component and the storm ater infiltrationany OWTS component and the stormwater infiltration system may be reduced to 15 feet if the stormwater infiltration system has been designed in accordance with RI St t D i d I t ll ti St d d M lRI Stormwater Design and Installation Standards Manualor RI Stormwater Management Guidance for Individual Single-Family Residential Lot Development.

Table 22.1- Page 46Leachfield

(ft)

Building Sewer, Grease Tank, Distribution Box, Pump Tank, Septic Tank, Septic Tank

Effl Pi (f )

Leachfield(ft)

Building Sewer, Grease Tank, Distribution Box, Pump Tank, Septic Tank, Septic Tank

Effl Pi (f )

(ft)Design Flow (gpd)

2510(Note 1)Water Supply Line

5025Well Serving Non-potable Uses

(ft)Effluent Pipe (ft)

(ft)Design Flow (gpd)

2510(Note 1)Water Supply Line

5025Well Serving Non-potable Uses

(ft)Effluent Pipe (ft)

min. 50 (Note 4)

> 5000Note (3)

50>2000-5000 Note (2)

100-2000

( )g (gp )

10(Not applicable to building sewer and septic

tank effluent pipe)Property Line

min. 50 (Note 4)

> 5000Note (3)

50>2000-5000 Note (2)

100-2000

( )g (gp )

10(Not applicable to building sewer and septic

tank effluent pipe)Property Line

25(Note 7)

50(Note 8)

25(Note 6)

25(Note 6)

Subsurface drains, foundation drains , or storm drains (see also Tables 22.2 and 22.3):-- Upgradient of the OWTS:

Downgradient and side gradient of the OWTS:

25(Note 5)

5(Not applicable to building sewer)Foundation

25(Note 7)

50(Note 8)

25(Note 6)

25(Note 6)

Subsurface drains, foundation drains , or storm drains (see also Tables 22.2 and 22.3):-- Upgradient of the OWTS:

Downgradient and side gradient of the OWTS:

25(Note 5)

5(Not applicable to building sewer)Foundation

2510Swimming Pools:

2525Stormwater Infiltration System

1010Edge of any land at a level lower than the invert of the distribution line

(Note 8)(Note 6)-- Downgradient and side gradient of the OWTS:

2510Swimming Pools:

2525Stormwater Infiltration System

1010Edge of any land at a level lower than the invert of the distribution line

(Note 8)(Note 6)-- Downgradient and side gradient of the OWTS:

Design Flow ≥5000 gpd (Note

3)

Design Flow <5000 gpd


3)


1010In-ground:Above ground:


3)



3)


1010In-ground:Above ground:

100505025

Coastal Shoreline Feature (Note 9) not in a Critical Resource Area, Flowing Water (Rivers and Streams), Open Bodies of Water (Lakes and Ponds), Other Watercourses Not Mentioned Above, and Any Stormwater Management Structure That Potentially Intercepts Groundwater

100505025

Coastal Shoreline Feature (Note 9) not in a Critical Resource Area, Flowing Water (Rivers and Streams), Open Bodies of Water (Lakes and Ponds), Other Watercourses Not Mentioned Above, and Any Stormwater Management Structure That Potentially Intercepts Groundwater

Table 22.1- Page 46

Note 11: The minimum setback distance from the ocean or Narragansett Bay is either fifty (50) feet or twenty five (25) feet plus the CRMC l l t d h li h tb kCRMC calculated shoreline change setback pursuant to the CRMP Section 140, whichever is greater This setbackwhichever is greater. … This setback distance is doubled for OWTSs with design flow greater than five thousand (5000) g ( )gallons per day.

All setbacks are doubled for OWTS ≥ 5000 gpd.

Swales:

Paved = 200’ Setback

Unpaved, < 200’ long = 200’ Setback

Unpaved ≥ 200’ long =Unpaved, ≥ 200 long = 100’ Setback

Table 22.2 - Page 49

Note 2: Distances measured from themeasured from the yearly high water mark.


Note 3: Distance may be reduced when seamless sleeves are used.

Swales:

Paved = 200’ S tb kSetback

Unpaved < 200’= 200’ Setback

Unpaved ≥ 200’= 150’ Setback

All setbacks are doubled for OWTS ≥

5000 gpd.

Table 22.3 – Page 50


Note 3: The minimum setback distance from the N tt B i ith fift (50)ocean or Narragansett Bay is either fifty (50)

feet or twenty-five (25) feet plus the CRMC calculated shoreline change setback whichevercalculated shoreline change setback, whichever is greater. This minimum setback distance is doubled for OWTSs with design flow greater doub ed o O Ss des g o g ea ethan five thousand (5000) gallons per day.


• CRMC Shoreline Change Maps


Note 2: Distance may be reduced when seamless sleeves are used.when seamless sleeves are used.

Table 22.4- Minimum Setback Distances from Drinking Water Wellsg

Note 1: Large Systems- These distances are minimum distances for large systems asminimum distances for large systems as defined in Rule 35.1. Greater distances may be required based on the Impactmay be required based on the Impact Analysis in Rule 35.3

Table 22.4 Minimum Setback Distances from Drinking Water Wellsg

Note 2: Distance from the building sewer may be reduced when the building sewermay be reduced when the building sewer is constructed of Schedule 40 PVC or equivalentequivalent.


Note 3: Distances may be reduced to 80/60/40 feet for yresidential OWTSs on lots 10,000 sq. ft. and larger if:

(A) The design flow is less than five hundred (500) gallons per day;

(B) The OWTS utilizes a Department approved Category 1 nitrogen reducing technology;

(C) The OWTS discharges to a PSND designed in d i h DEM id li daccordance with DEM guidelines; and

(D) The OWTS separation distance to groundwater is th (3) f t tthree (3) feet or greater.


Note 4: The minimum setback distances shall be ote e u setbac d sta ces s a beincreased to 150/100/75 for OWTSs with a design flow of less than 1000 gallons per day if des g o o ess a 000 ga o s pe daythe OWTS is designed for Category 1 soils. For such OWTSs utilizing a BSF or PSND gconstructed in accordance with DEM guidelines, the minimum setback distances may g , ybe 100/75/50.

Rule 32 4: Depth to GroundwaterRule 32.4: Depth to GroundwaterThe leachfield shall be located in an area

h th SHGT i i i f t (2)where the SHGT is a minimum of two (2) feet below the original ground surface. On l t 20 000 ft l th l hfi ldlots 20,000 sq. ft or larger, the leachfield may be located in an area where the SHGT i l th t t f (24) i hSHGT is less than twenty-four (24) inches but greater than or equal to eighteen (18) i h f th i i l d f ifinches from the original ground surface if the OWTS utilizes a bottomless sand filter and the applicant has no arianceand the applicant has no variance requests.

Rule 32.5: Depth to Restrictive L B d kLayer or Bedrock

Th l hfi ld h ll b l d iThe leachfield shall be located in an area where a restrictive layer or bedrock is a

i i f f (4) f b l h i i lminimum of four (4) feet below the original ground surface. The minimum depth to a

t i ti l b d k h ll b trestrictive layer or bedrock shall be met within twenty-five (25) feet of all sides of th l hfi ldthe leachfield.

Vertical Separation Distance:Groundwater

Rule 32.7: The bottom of the stone underlying the leachfield shall be at least three (3) feet above the seasonal high groundwater table.

Vertical Separation Distance: Groundwater

In the Salt Pond and narrow River Critical Resource Areas and

Rule 39 5 and 40 3: The bottom of the stone

In the Salt Pond and narrow River Critical Resource Areas andIn Drinking Water Supply Watersheds

Rule 39.5 and 40.3: The bottom of the stone underlying the leachfield shall be at least four (4) feet above the seasonal highfour (4) feet above the seasonal high groundwater table when either soil category 1 2 3 4 or 6 are encountered incategory 1, 2, 3, 4, or 6 are encountered in determining the maximum leachfield loading rateloading rate

Vertical Separation Distance:R i i L B d kRestrictive Layer or Bedrock

Rule 32.8: The bottom of the stone underlying the leachfield shall be at least 5 feet above a

frestrictive layer or bedrock. This 5 foot vertical separation shall be maintained to a distance of 25 feet from the side wall of the leachfield. In the upgradient direction, the 5 foot vertical separation may be waived as long as the restrictive layer or bedrock is no higher than therestrictive layer or bedrock is no higher than the bottom of the stone within 25 feet of the leachfield.

Excavating into a restrictive layer or bedrock is notExcavating into a restrictive layer or bedrock is not permitted.

What if a Design Can’t Meet S b k R i ?Setback Requirements?

• You can:You can:– Change the design, or– Request a Variance.q

• DEM may grant a variance to setbacks but WILL NOT APPROVE requests for the following…

(Rule 48.2.2 lists all scenarios where request for variance will not be approved.)

Rule 48.2 Variance Review Standards -Denials

48.2.2(E)- Denial(ii) The variance request is from the requirements of Rule 14 2(ii) The variance request is from the requirements of Rule 14.2

on a site located in the Salt Pond or Narrow River Critical Resource Areas unless the applicant demonstrates that a net reduction in overall, long-term nitrogen loading to the watershed will result.

(Rule 14.2- Any dwelling or other building having plumbing fixtures from which wastewater is produced, where no public wastewater system is available or accessible, shall be provided with an OWTS. All of the components of such OWTS shall be located within the property boundary upon which the building or dwelling is located.)

Rule 48.2 Variance Review Standards -Denials

48.2.2(E)

(vii) The variance request is for less than the(vii) The variance request is for less than the eighty (80) foot minimum setback distance from a private drinking water well;from a private drinking water well;

(ix) The variance request is for a depth to groundwater from original ground surface of less than twelve (12) inches or for a depth to a restrictive layer or bedrock of less than thirty six (36) inches;

Examples!

Table 22.1: Minimum Distances

non-potable wellnon potable well

25’ to BS, grease trap

potable well

g ppump tank, septic tank, ST effluent pipe

50’ to leachfield


non-potable well

potable well

p

10’ to BS, grease trap pump tank, septic tank ST effluent pipetank, ST effluent pipe

25’ to leachfield


potable wellpotable well

foundation (25’); no drain (15’); slab (8’)

t li (10’)

5’ to grease trap t k ti

property lines (10’) (all components but BS and ST-EP)

pump tank, septic tank, ST-EP


private wellprivate well

fill perimeter (10’)

fill perimeter (10’)

Table 22.1: Minimum Distances- Foundation

DrainDrain

25’ to BS grease trap25’ to BS, grease trap pump tank, septic tank, ST effluent pipe

Table 22.1: Minimum Distances- Foundation Drain

50’ downgradient

50’ in all directions if slope < 3%

Table 22.1: Minimum Distances- Foundation DrainLake (not a drinking

water supply)water supply)

25’ Upgradient

50’ in all directions if < 3%

Table 22.1: Minimum Distances- Storm Drain

25’ if the drain is watertight bedded inwatertight, bedded in sand or bank run gravel, or laid at an elevation above the seasonal high groundwater table

Table 22.1: Minimum Distances- Above

Ground PoolGround Pool

10’10 10’

Table 22.1: Minimum Distances- In-Ground

PoolPool

10’10 25’

Minimum Distances: Wells and Water

Suppliesprivate well

Gravel packed well

DRINKING WATER SuppliespWATER SUPPLY

water line (10’)

water pressure line (25’)water pressure line (25 ) new system

Lakenew system

Lake

all components (25’)

cesspool

Table 22.1: Minimum Distances-

Watercourses Not in aWatercourses Not in a CRA

Table 22.1: Minimum Distances Not in

DW/CRA

new system

Table 22.1: Minimum Distances Not in

DW/CRADW/CRA

flagged edge of wetlandwetland

new system

Table 22.2: Minimum Distances in DW

WatershedWatershed

flagged edge of wetlandwetland

new system

Definitions – Salt Pond and Narrow Ri C i i l R ARiver Critical Resource Areas

Areas designated as CRA’s include:g

Cards PondTrustom Pond

Point Judith Pond

Quonochontaug Pond

Potter Pond Trustom Pond

Ninigret Pond

Winnapaug Pond Maschaug Pond

Ninigret Pond

Green Hill Pond

p g

Narrow River and its watershed

new system


SALT PONDwell

cesspool

p ( )

Table 22.3: Minimum Distances- Salt

Pond/Narrow River CRA

Definitions – Drinking Water Supply W h d C i i l R AWatershed Critical Resource Areas

Drinking water reservoirs and their watershedsDrinking water reservoirs and their watersheds for the following water suppliers:

P id Newport

Eleanor Slater Hospital

Providence NewportWoonsocket

Cumberland Bristol County

Jamestown PawtucketStone Bridge FD

New ShorehamStone Bridge FD

Yawgoog Scout Reservation

DRINKING WATER

new system


WATER SUPPLY

cesspool

Table 22.2: Minimum Distances- DrinkingDistances- Drinking

Water Supply Watershed CRA

Any Questions??

regulatory setbacksregulatory setbacks and buffersand

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