How to Manage and Control Storm Water Runoff

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This fact sheet examinespotential risks to the environmentand your health from storm waterrunoff. Two areas are covered:

Part 1. Reducing pollutants inrunoff. Pollutants can includepesticides and chemicals, automo-tive wastes, grass clippings and

yard waste, pet and animalmanure, and winter salt and de-icers.

Part 2. Landscaping and sitemanagement to control runoff.Some ways to help control runoffare preventing soil erosion, pro-viding basement flood protection,landscaping, providing properroof drainage, and minimizingpaved surfaces.

Completing this fact sheet will

help you evaluate how stormwater affects the environmentalquality of your property andproperties downstream. You willalso learn ways to reduce pollu-tion risks.

What is storm water?

Storm water is water from rainor melting snow that does notsoak into the ground. It flows

from rooftops, over paved areasand bare soil, and through slopedlawns. As it flows, this runoff col-lects and transports soil, petmanure, salt, pesticides, fertilizer,oil and grease, leaves, litter andother potential pollutants.

You dont need a heavy rain-storm to send pollutants rushingtoward streams, wetlands, lakesand oceans. A garden hose alonecan supply enough water.

Even if your house is not on awaterfront, storm drains and sew-ers efficiently convey runoff fromyour neighborhood to the nearestbody of water. Contrary to popu-lar belief, most storm sewers do

not carry storm water to waste-water treatment plants (see figure2.1 on page 2). Storm and sanitarysewers may be combined in someolder communities.

Why should yoube concerned?

Polluted storm water degradesour lakes, wetlands and rivers.Soil clouds water and degradeshabitat for fish and water plants.Nutrients such as phosphorus and

nitrogen promote the growth ofalgae, which crowds out otheraquatic life. Toxic chemicals, suchas antifreeze and oil from leakingcars, carelessly applied pesticides,and zinc from galvanized metalgutters and downspouts, threatenthe health of fish and other aquat-ic life. Bacteria and parasites frompet manure can make nearbylakes and bays unsafe for wadingand swimming after storms.

As many people have discov-ered, storm water can be a prob-lem closer to home. It can flowinto basements and cause damagethat is difficult and costly to cleanup. Storm water can also flowdown a poorly sealed well shaftand contaminate drinking water.In areas with very porous soils orgeology, pollutants in runoff mayreach groundwater.

Public officials are focusingpollution control efforts on storm

water management in urban andrural areas. Storm water pollutioncannot be treated in the same wayas water pollution from dischargepipes, because it comes frommany sources (see table on page 2).

It is carried by storm waterfrom every street, parking lot,sidewalk, driveway, yard and gar-den. The problem can only besolved with everyones help.

How to Manage andControl Storm Water Runoff

HomeASystEnvironmental Risk Assessment Guide Fact Sheet 2 muextension.missouri.edu/ xplor/

Published by MU Extension, University of Missouri-Columbia Fact Sheet 2 EQM102


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Storm Water: Part 1

Reducing pollutants in runoffStorm water is unavoidable,

but its effects can be reduced bykeeping harmful chemicals andmaterials out of runoff. This sec-

tion reviews potential sources ofcontamination and offers ways tominimize them.

When you finish reading thissection, fill out the work sheet tohelp identify storm water risks onyour property.

W here does storm wa ter go?The next time you are home

during a rain shower, head out-doors with your boots and

umbrella and watch where therainwater goes.

On a sketch of your property,draw arrows showing the direc-tion that storm water flows offdriveways, rooftops, sidewalks,and yards. A sample map is pro-vided infigure 2.2. (Instructionsfor making a homesite sketch canbe found in Fact Sheet 1.) Does

water soak into the ground quick-ly, or does it puddle in places and

flow off lawns and driveways?Your soil type affects water infil-tration (soaking into the ground).As you might expect, water infil-trates sandy soil quickly but has ahard time seeping into fine-grained silt or clay soils.

During your walk, note howfar it is to the nearest storm sewer,ditch, wetland, stream or body of

open water. Note whether runoffflows onto your land from adja-

cent streets, lands or storm watersystems. If you live at or near thebottom of a hill, you may havespecial problems. Be sure to goout during more than one rainshower to get a good understand-ing of runoff flow during smalland large storms.

Figure 2.1. Runoff that flows intostorm sewers goes directly tostreams and lakes without treatment.

POLLUTANT COMMON SOURCES

Silt, sand, and clay Construction sites; bare spots in lawns and gardens;particles and other wastewater from washing cars and trucks on drive-debris. ways or parking lots; unprotected stream banks.

Nutrients Over-used or spilled fertilizers; pet manure; grassclippings and leaves left on streets and sidewalks;leaves burned in ditches.

Disease organisms Pet manure and garbage.

Hydrocarbons Car and truck exhaust; leaks and spills of oil andgas; burning leaves and garbage.

Pesticides Pesticides over-applied or applied before a rain-storm; spills and leaks.

Metals Cars and trucks (brakes and tire wear, exhaust);galvanized metal gutters and downspouts.

Common sources of storm water pollutants

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Are any car or truck wastes beingcar r ied a w ay by storm w ater?

Oil stains on your drivewayand outdoor spills of antifreeze,brake fluid, and other automo-tive fluids are easily carried awayby a rainstorm. An oily sheen on

runoff from your driveway is asure sign that you need to bemore careful.

Use pans, carpet scraps ormatting to catch drips. Routinemaintenance can prevent yourcar from leaking and help identi-fy potential leaks. If you changeyour own oil, be careful to avoidspills and collect waste oil forrecycling.

Oily car parts and fluid con-tainers should be stored where

rain and runoff cannot reachthem. Never dump used oil,antifreeze, or gasoline down astorm drain, in a ditch, or on theground. These wastes will end upin a nearby lake or stream, or theymay pollute your drinking water.

Washing your car in the dri-veway creates runoff without thehelp of a rainstorm your hoseprovides the water. The dirty,soapy runoff drains directly into

storm sewers, picking up oil andother pollutants as it goes. Trywashing your car on the lawn or,better yet, take it to a commercialcar wash or spray booth thatsends its dirty water to a waste-water treatment plant.

Are household products storedoutside the reach of storm water?

Most households store lawnand garden products like weed

killers, insect killers and fertiliz-ers. If storm water or floodwaterreaches these products, it cantransport them into surface waterand possibly your well.

Pool chemicals, salt for watersofteners, and a wide variety ofother chemical products can alsocause trouble if they are washedaway.

Keeping such products inwaterproof containers and storingthem up high and out of thepotential path of runoff or floods isimportant. You can avoid storageproblems by buying only whatyou need for a particular task andthen using up the product.

Prevent freezing of liquid prod-ucts. Most pesticides, and some

fertilizers, are liquid and may besubject to freezing. This may burstcontainers or render the productunusable.

Do you use and handlechemicals safely?

Safe storage is only the firststep in preventing contaminatedrunoff. When mixing chemicals,try to do it within a washtub sospills will be contained. If you

spill chemicals, act quickly tocontain and clean up the spill.This is particularly important onpaved surfaces.

Using more pesticides or fertil-izers than you need invites prob-lems. Timing of applications is alsoimportant. Do not apply pesticidesand chemicals if rain is expectedwithin twenty-four hours.

Read all pesticide labels care-fully for application instructionsand restrictions.

See Fact Sheet 5, Yard andGarden Care, for more informa-tion on the proper use and han-dling of yard and garden prod-

ucts.

Do you use road salt orother d e-icing prod ucts?

Road salt and de-icers even-tually wash off paved surfacesand end up in the soil or water.From your driveway or side-walk, salt can readily flow tostorm drains and into streamsand lakes.

Salt in high concentrations is

harmful to wildlife and plants.Use less to keep these chemicalsout of natural systems. If youuse too much, clean up theexcess. Consider sand or regularkitty litter as less toxic alterna-tives. Chipping ice off pave-ments is an even better choice,although care must be taken notto damage the pavement surface.

How is animal manure kept frombecoming a pollution p roblem?

Droppings from dogs and catsand from other commonly keptanimals like exotic birds, rabbits,goats and chickens can be trou-blesome in two ways. First,manures contain nutrients thatcan promote the growth of algaeif they enter streams and lakes.Second, animal droppings are asource of disease.

The risk of storm water conta-

mination increases if pet manuresare allowed to accumulate in ani-mal pen areas or if they are lefton sidewalks, streets or drive-ways where runoff can carrythem to storm sewers.

Droppings that are not mixedwith litter or other materialsshould be flushed down the toi-let. Or, if local laws allow it,

Figure 2.2. Map showing direction

of surface runoff and stream flow.

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droppings may either be buriedor wrapped and put in thegarbage for disposal.

Are yard and garden w asteskept out of storm water?

If left on sidewalks, drive-ways, or roads, grass clippingsand other yard wastes will washaway with the next storm (see fig-ure 2.1, page 2).

Although leaves and otherplant debris accumulate naturallyin streams and lakes, homeownerscan contribute excess amounts ofplant matter, especially in areaswith many homes. This can leadto water that is unattractive orgreen with algae and unsuitablefor recreation.

Burning yard waste is not anenvironmentally friendly alterna-tive, and its illegal in some areas.Hydrocarbons and nutrients

released by burning leaves con-tribute to water pollution as wellas air pollution.

Rain washes smoke particlesout of the air, and runoff picks updust and ashes left on pavementor in ditches.

Avoiding the problem is easy sweep clippings back onto thegrass, and compost leaves andgarden wastes on your propertyto recycle nutrients.

Assessment 1:Reducing pollutants in runoff

Use Assessment 1 in theaccompanying work sheet to rateyour storm water pollution risks.

For each question, indicate yourrisk level in the right-hand col-umn. Some choices may not corre-spond exactly to your situation.Choose the response that best fits.Refer to the sections above if youneed more information.

Storm Water: Part 2Landscaping and site managementto control storm water runoff

Some storm water risks can becontrolled by making changes tobuildings, paved surfaces, thelandscape and soil surfaces. Thissection reviews some easilyaddressed problems as well asmajor landscape alterations youmight want to consider.

Are there areas of baresoil around your hom e?

Areas of bare soil often exist invegetable and flower gardens, onnewly seeded lawns, and aroundconstruction projects. Even ongentle slopes, water from rain and

snow can remove large amountsof soil and carry it to wetlands,rivers and lakes.

Planting grass or other groundcovers is the best way to stop ero-sion. Putting a straw or chipmulch over gardens or newlyseeded areas will slow erosion.Straw bales, diversion ditches andcommercially available silt fencesaround construction sites can helpslow runoff and trap sediment on-site. If you are working with a

contractor, insist that precautionsare taken to control runoff anderosion during construction.

Can y ou eliminate pa ved surfacesor install a lterna tives?

Concrete and asphalt roads,driveways and walkways preventrainwater from soaking into theground. When you have thechoice, consider alternative mate-

rials such as gravel or wood chipsfor walkways.Avoid paving areas such as

patios. Where you need a moresolid surface, consider using aporous pavement made frominterlocking cement blocks or rub-ber mats that allow spaces forrainwater to seep into the ground.If you must pour concrete, keepthe paved area as short and nar-row as possible.

Is your basement protected fromstorm water seepage or flooding?

Storm water in your basementcan be a hazard in two ways: first,if water carries contaminants ordisease organisms into yourhome, and second, if water picksup chemicals stored in your base-ment and carries them into the

Figure 2.4. Roof drainage should be

directed to the lawn or a flower bed

and away from the foundation and

paved surfaces.

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sewer or ground. Basement win-dows or doors are common stormwater entry points and should be

sealed against leaks.It is best if window and door

sills are at least a foot aboveground level. If windows are at orbelow ground level, they can beprotected with clear plastic coversavailable in building supplystores. Window wells that extendabove ground level can helpdivert storm water. Your yardshould be sloped away from thefoundation to prevent water from

pooling near the house and leak-ing into the basement.

Does roof water flowonto pavement or grass?

Your house roof, like pave-ment, sheds water. If downspoutsfrom roof gutters empty ontograssy areas, the water will have achance to soak into the ground.Aim downspouts away fromfoundations and paved surfaces

(see figure 2.4 on page 4). For roofswithout gutters, plant grass,spread mulch, or use gravel underthe drip line to prevent soil ero-sion and increase the groundscapacity to absorb water.Consider using cisterns or rainbarrels to catch rainwater forwatering lawns and gardens indry weather.

Can you chang e your la ndscap eslayout to reduce runoff?

An essential part of storm

water management is keepingwater from leaving your property,or at least slowing its flow as muchas possible. Many home lawns aresloped to encourage water to runoff onto neighboring property orstreets. Instead, you could providelow areas landscaped with shrubsand flowers to encourage water tosoak into the ground. If your yardis hilly, you can terrace slopes toslow the flow of runoff and make

mowing and gardening easier.If you have a large lot, consid-er naturalizing areas withprairie, woodland or wetlandplants. If your property adjoins alake or stream, one of the bestways to slow and filter runoff isto leave a buffer strip of thick veg-etation along the waterfront (see

figure 2.5, above).Good sources for ideas are

your local University Outreachand Extension center, Natural

Resources Conservation Service,or Soil and Water ConservationDistrict offices.

Assessment 2: Landscaping andsite ma nag ement tocontrol storm water runoff

For each question in assess-ment 2 on the work sheet, indicateyour risk level in the right-handcolumn. Select the answer thatbest matches your situation. Referto part 2 above if you need moreinformation to complete the table.

For more informationContact your local University

Outreach and Extension center,the Missouri Department ofNatural Resources TechnicalAssistance Program, or NaturalResource Conservation ServiceUrban Conservationist for infor-mation on landscaping, nonpointsource pollution, and storm watermanagement techniques.

Resources and

publicationsBay Book: A Guide to ReducingWater Pollution at Home (1993).Available from the ChesapeakeRegional Information Service(CRIS), a project of the Alliancefor the Chesapeake Bay, 6600 YorkRoad, Baltimore, MD 21212; (800)662-2747.

Figure 2.5. To help prevent erosion, leave an unmowed buffer strip

of thick vegetation along stream banks and lakeshores.

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From University of MissouriExtension Publications, 2800McGuire Blvd, Columbia, MO65211; phone: 573/882-7216; seeWM 6011: Storm Drains andWater Quality; http://muexten-sion.missouri.edu/xplor/waste-man/wm6011.htm

The following publicationsrelating to storm water runoff areavailable from the University ofWisconsin Extension Publications,Room 170, 630 West Mifflin Street,Madison, WI 53703-2636; (608)262-3346.

Up to five copies are free; callfor price information if you wantmore than five copies.

Storm Sewers: The RiversBeneath Our Feet (GWQ004)

Cleaning Up Storm WaterRunoff (GWQ016)

Beneficial Landscape Practices(GWQ008)

Car Care for Cleaner Water(GWQ019)

Lawn and Garden Fertilizers(GWQ002) Shoreline Plants and

Landscaping (GWQ014) Lawn and Garden Pesticides

(GWQ011) Lawn Watering (GWQ012) Pet Waste and Water Quality

(GWQ006) Practical Tips for Home and

Yard (GWQ007)

Pollution prevention at homehelps ensure your safety

For more information abouttopics covered in the MissouriHomeASyst series, or for infor-mation about laws and regula-tions specific to your area, contactyour nearest University Outreach

and Extension center.

Contact the MissouriFarmASyst/HomeASystProgram at: 205 AgriculturalEngineering Building, Universityof Missouri-Columbia, Columbia,MO 65211; phone 573-882-0085.

Issued in furtherance of Coop erative Extension W ork Acts of M ay 8 and June 30, 1914, in coop eration w ith the U nited States D epartm ent

of Ag riculture. Ronald J. Turner, D irector, C ooperative Extension, U niversity of M issouri and Lincoln U niversity, C olum bia, M O 65211.

U niversity O utreach and Extension does not discrim inate on the b asis of race, color, national origin, sex, religion, ag e, disability or status

as a Vietnam era veteran in em ploym ent or program s. If you have sp ecial needs as addressed by the Am ericans w ith D isabilities A ct and

need this pub lication in an alternative form at, w rite AD A O fficer, Extension and Agricultural Inform ation, 1-98 Agriculture B uilding , Colum bia,

M O 65211, or call (573)882-7216. Reasonab le efforts w ill be m ade to accom m odate your special need s.

OUTREACH & EXTENSION

UNIVERSITY OF MISSOURI

COLUMBIA

This guide was prepared by Steve Mellis and Don Schuster, based on the HomeASyst chapter written by Carl DuPoldt,

Environmental Engineer, Natural Resources Conservation Service, Somerset, New Jersey and Carolyn Johnson, WaterQuality Education Specialist, University of Wisconsin Cooperative Extension, Milwaukee.

The MissouriHomeASyst series was produced with funding from the United States Department of Agriculture and wasadapted for use in Missouri from the National FarmASyst/HomeASyst Program in Cooperation with the NortheastRegional Agricultural Engineering Services (NRAES).

$1.25 Fact Sheet 2 EQM102 New 4/ 01/ 3M

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An Introduction to Assessing the Environmental Safety of

Your Home ($.75) .......................................................................................EQM100

Site Assessment: Protecting Water Quality

Around Your Home ($1.25)......................................................................EQM101

How to Manage and Control Storm Water Runoff ($1.25) ......................EQM102

Drinking Water Well Management ($1.50) .................................................EQM103

Household Wastewater: Septic Systems and Other

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HomeASyst Risk Assessment Guide ($4.00).........................................EQM106

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How to Manage and Control Storm Water Runoff