Impending Stormwater Compliance LID_Stor… · 2/27/2015 6 Municipal Stormwater Regulations MS4 Permit Requirements • Regulated Projects ‐LID Design Standards – ≥5,000 ft2

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ImpendingStormwater Compliance

for Contractors & Developers

P t d TPresented To:

Humboldt Builder’s Exchange

February 27, 2014

Presented By:

Streamline Planning Consultants

Sam Polly, CPESC, QSD/QSP

Bob Brown, AICP 2

• Water Quality Regulation Overview• The New MS4 Regulations• CalculationsLID Pl i L

Topics Covered

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• LID Planning LessonsLearned

MS4 = Municipal Separate Storm Sewer System (A municipality)

Polluted Runoff

Polluted Runoff is the #1 Polluted Runoff is the #1 Water Quality Problem Water Quality Problem in California & the U.Sin California & the U.S. .

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(U.S. EPA)(U.S. EPA)

The only purpose of a street gutter/ storm drain is to put pollutants into our streams.

Old School New School

Managing Stormwater

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• Traditional Stormwater Management = “Gray Infrastructure”Collection, Conveyance, Discharge

Approaches to Stormwater Management

• Low Impact Development

= “Green Infrastructure”

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Today’s Problem

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Today’s Problem

• Bad Attitude?• Working in the Rain? Sediment

• Cleaning his Sprayer at the

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Sprayer at the Storm Drain Inlet? Water soluble?

• Downspout extension to curb hole

The Current Regulatory Climate:Avoid this scene

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The Current Regulatory Climate:Avoid this kind of mail

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The Current Regulatory Climate:Stormwater

• CWA & Porter Cologne – everyone is liable regardless of permit

• Agriculture ‐ dairies & now vineyards, livestock, lilies• Industrial ‐ SIC Codes such as creameries, contractor

yards asphalt plants wood workers

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yards, asphalt plants, wood workers…• Construction ‐ > 1 acre disturbed• MS4 – ≥2,500 ft2 will now have stormwater requirements

July 1, 2015

• What does this mean?– Confusion for everyone: 289 pgs, 76 p. fact sheet– Additional costs/ Potential development size reduction

Municipal Stormwater RegulationsPhase II Small MS4 General Permit

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– Increased building permit difficulties – Transparency of municipalities to the whole world– So municipalities MUST strictly enforce MS4 regulations

– Plans & projects MUST be in compliance for building permits, occupancy, profit & reputation

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Practice Tip #1 Get you building permit approvals before July 1st

– What happens if you submit an application on June 15th and it gets turned back for corrections


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gon June 30th?

– After July 1st, get pre‐application consultation– After July 1st, prepare SWCP (Storm Water Control Plan)

Whose watching?• California State Water Resources Control Board• Regional Water Resources Control BoardL l M i i lit ( )


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• Local Municipality (Permittee) • Neighbors• 3rd Party Watchdog Groups • & Lawyers

Whose in? – Larger urban areas– Cities:

• City Limits of: Fortuna, Eureka, Arcata• Smaller polygon within city limits: Trinidad


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– County:• Unincorporated town: McKinleyville• Resort Improvement District: Shelter Cove• Communities surrounding Eureka: Bayview, Cutten, Ridgewood Heights, Humboldt Hill, Myrtletown

– Others: School Districts, HSU, State Parks, etc.

• Whose out? – Smaller urban areas– Towns: Manilla, Samoa, King Salmon, Fields Landing, Willow Creek, Rio Dell, GarbervilleRural Neighborhoods & woods: Areas outside the


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– Rural Neighborhoods & woods: Areas outside the MS4 Permit boundary maps


SMARTS

SMARTS Webpage: Scroll down…

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Click here!

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Click Here

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After clicking the SW Data box, Scroll down again to:

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After clicking the Search for Owners/Operators, use the dropdown menu for the Application Type and fill in the Owner, then click the Search box:

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Click View Attachments:

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Click Facility/Site Map:

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H u m b o l d t B a y

J G

HK

E FPALCOMARSH

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City of Eureka: MS4 Jurisdiction

23Figure 2- Drainage Basins &Stormwater Outfall Locations

Drainage Basin Boundaries

CB

A M

Legend

Outfalls

Storm Drain Sewer Mains

O City Boundary

BASINA

B

C

D

E

F

G

H

I

J

K

L

M

O

PALCOMARSH

24County of Humboldt: MS4 Jurisdiction

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City of Fortuna: MS4 Jurisdiction

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City of Arcata: MS4 Jurisdiction

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27City of Trinidad: MS4 Jurisdiction

Municipal Stormwater RegulationsMS4 Permit Requirements

• Small Projects– 2,500 to 5,000 ft2 of replaced or created impervious surfaceSingle family home projects ≥ 2 500 ft2

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– Single family home projects ≥ 2,500 ft2

– Must use 1 or more Site Design Measure (SDM)– Must quantify runoff reduction from SDMs

Practice Tip #2– Keep your new or remodel projects (impermeable surfaces of building, driveways, parking, etc) to less than 2,500 s.f.


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,– Design so minimal impervious surfaces. ‘Cut corners’ where you can.


• Regulated Projects– ≥ 5,000 ft2 of replaced or created impervious surface– Single family home projects excluded– Must use maximum Site Design Measures (SDMs)

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Must use maximum Site Design Measures (SDMs)– Must incorporate Source Controls– Must use LID Design Standards for maximum runoff reduction and to treat remaining runoff

– Must quantify runoff reduction– Annual reports demonstrating proper O&M

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• Regulated Projects ‐ LID Design Standards– ≥ 5,000 ft2 of replaced or created impervious surface– Perform Site Assessment – quantify runoff reduction– Map Drainage Management Areas (DMAs)

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– Employ Numeric Sizing Criteria of the 85th percentile, 24‐hour runoff volume (0.65”)

– Must use maximum Site Design Measures (SDMs)– Must incorporate Source Controls– Must treat the remaining 85th percentile runoff using “Bioretention”


• Regulated Projects – Operation & Maintenance:Post‐Construction Storm Water Management Measures– Project proponent’s signed statement of responsibility

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for O&M until legally transferred or,– Written conditions in sales/lease agreements/deeds requiring buyer or lessee responsibility until legally transferred

– Conditions of approval, etc. granting site access to Permittee for O&M inspections


• Regulated Projects – Condition Assessment:Post‐Construction Storm Water Management Measures

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– Annual reports to jurisdictional Permittee

Practice Tip #3– Keep your new or remodel projects (impermeable surfaces of building, driveways, parking, etc) to less than 5000 s.f.


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– Design so minimal impervious surfaces. ‘Cut corners’ where you can.

Practice Tip #4– Design your new or remodel projects (impermeable surfaces of building, driveways, parking, etc) so that each DMA drains to large


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p g, ) genough landscape area.

– This requires shifting project on lot, regradingdriveway features, reconsider downspout locations

Municipal Stormwater Calculations

• Regulated Projects – Runoff CalculationRequirement– Increase >50% impervious on redevelopment then Ronoff from ALL (existing + new) impervious is

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Ronoff from ALL (existing + new) impervious is included;

– <50% increase = only the new impervious is included in calculations

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Municipal Stormwater Calculations

• Methods– Dictated by local jurisdiction

– Local LID ManualC l l t

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– Calculator– Manual

– Each method has advantages and drawbacks

Residential

16,500 sf lot

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Residential

16,500 sf lotResidence 4000 s.f.Concrete 4000 s.f.Imp. Surface: 8000 s.f.Landscaping 8500 s.f.

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Residential

Current Practice:•Grade the lot so you can get all stormwater to driveway and out

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onto street

Residential DMA’s

MS4 Requirement•Minimize Disturbed area•Minimize Impervious surfaces•Design Grading Plan

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•Design roof downspouts•Define DMA’s•Perform Calculations•Add Site Design Measures

DMA = Drainage Management Area

Residential DMA’s

DMA CalculationDMA = Drainage Management Area

DMARoof (sf)

Concrete (sf)

Landscape (sf)

Total (sf)

1 700 800 200 1700

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2 900 1800 900 3600

3 1700 0 4100 5800

4 700 1400 3300 5400

Total 4000 4000 8500 16500


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Residential DMA’s

DMA CalculationDMA = Drainage Management Area

DMA Roof (sf) Concrete (sf) Landscape (sf) Total (sf)

1 700 800 200 1700

1500/2 (need 750) short 550

2 900 1800 900 3600

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2 900 1800 900 3600

2700/2 (need 1350) short 450

3 1700 0 4100 5800

1700/2 (need 850)extra 3250

4 700 1400 3300 5400

2100/2 (need 1050)extra 2150

total 4000 4000 8500 16500


Residential DMA’s

Site Design Measures•Rain Garden•Bioswale•Permeable Pavement•Trees

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•Rain Barrels•Etc


BioretentionRain Gardens and Vegetated Swales

By Timothy Lawrence45

Rain Gardens and Vegetated Swales

• Rain Garden


Vegetated Bioswales

Parking Lots

• Curb cuts drain roadways into ylandscaped LID

Bioretention Area Cross-section

By Timothy Lawrence 48

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DMA’s for Commercial or Multifamily

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Practice Tip #5 for Projects > 5000 sf (Regulated Projects)

– Bioretention may be worth it. 10,000 sf of impervious requires 400 sf bioretention.


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p q– Bioretention requires recording of O&M agreement on deed and submittal of annual O&M reports.

– Bioretention may not be worth it.

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Drainage Management Areas

• Step 1: Delineate the DMAs

• Step 2: Classify the DMAs

Page

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Drainage Management Areas Tabulation and CalculationsAreas draining to self‐retaining areas

DMA Square Feet

Surface RunoffFactor

Product Receiving DMA

ReceivingDMA Area

Ratio

8 1822 Roof 1.0 1822 DMA-7 79819 1712 Roof 1.0 1712 DMA-7 798110 2558 Roof 1.0 2588 DMA-7 7981∑ 6092 7981 0.76

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Municipal Stormwater Calculatorhttp://owp‐web1.saclink.csus.edu/LIDTool/Start.aspx

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Municipal Stormwater Calculator

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– If using a generalized web soil map, check your site’s soil to avoid excess Site Design Measures


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Municipal Stormwater Calculator0.16 ac = 6,970 ft2

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Municipal Stormwater Calculator

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One 55 gal rain barrel = 7.35 ft3 so multiply by 4 barrels = 29.4 ft3 = 22.4% reduction;Remaining 77.6% x 325ft2 = 252.2ft2 Amended Strip 18” deep (16’x16’ or 5’x50’)


– Consider available space versus up front cost & long‐term maintenance


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Municipal Stormwater RegulationsInterpretations

• Permit Goals vs. Manual Standards– E.12.e.(ii)(f)3)…minimum infiltration rate of 5 inches per hour…

– E.12.e.(ii)(f)3)… A mixture of sand (60%‐70%)…and

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compost (30%‐40%) may be used.– Really?

Municipal Stormwater RegulationsInterpretations

• Permit Goals vs. Manual Standards– What’s really sustainable and what works on the ground

– E.12.e.(ii)(f)…The facilities must be demonstrated

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to be at least as effective as a bioretentionsystem with the following design parameters:

– Doesn’t say “must have the following parameters”– E.12.e.(ii)(f)8) “Appropriate plant palette for the specified mix…” implies different mixes


– If the local jurisdiction allows, assess your soils before resorting to bioretention; an engineered

Municipal Stormwater RegulationsFlexibility

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g ; gsoil mix and associated impacts may be unnecessary

Microbes eat toxins for breakfast!

LID – What’s the Point

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Microbes eat hydrocarbons for lunch!

LID – What’s the Point

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LID – Creating a toxin-eating ecosystem

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Design Considerations and Requirements Considerations

• Irrigation? Soil, Compost/Mulch, Plant Type, Planting Season

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• Compaction– Surrounding Project Construction/Engineering

– Equipment within LID feature

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Follow local climate cycles ‐Native plants have dormant cycles

“Brown is the New Green”

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Cosumnes Elementary,Sloughouse, CAPhoto Courtesy of Delta Bluegrass

Practice Tip #9– Waterboard Intent = Development mimics natural landscape and ecosystem to reduce runoff and pollution


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p– Maximize soil‐plant‐microbial systems

Questions? ….No?

Waterboard• [email protected]• (866) 563‐3107

Streamline Planning• [email protected]• [email protected]• (707) 822‐5785

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BioretentionRain Gardens and Vegetated Swales

• Rain Garden


Pervious Concrete

• Minimize stormwater runoff• Reduce need for storm drain systems• Provide filtration of pollutants• Increase infiltration to groundwaterE li i t ddl !

Pervious Pavement

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Permeable Pavers

Reinforced Grass

• Even eliminate puddles!

Rain Barrels/Cisterns

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Design Considerations and Requirements Soils and Plants

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Where are the Roots?

Roots: Perennial vs. Annual

Impending Stormwater Compliance LID_Stor… · 2/27/2015 6 Municipal Stormwater Regulations MS4 Permit Requirements • Regulated Projects ‐LID Design Standards – ≥5,000 ft2

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