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4.5. STORM WATER RUNOFF MANAGEMENT

Management Measure for Storm Water Runoff:

Implement effective runoff control strategies that include the use of pollution

prevention activities and the proper design of hull maintenance areas.

Reduce the average annual loadings of total suspended solids (TSS) in runoff

from hull maintenance areas by 80 percent. For the purposes of this measure,

an 80 percent reduction of TSS is to be determined on an average annual

basis.

Management Measure Description

Any debris that is on the ground and light enough

to be swept away by flowing rainwater or snowmelt can end up in lakes, reservoirs, ponds, rivers,

streams, canals, bays, estuaries, or oceans.

Sanding dust, paint dust and chips, copper and

other heavy metals, and other such solids that are

carelessly or inadvertently allowed to drop to the

ground while maintaining or repairing a boat by

sanding, pressure washing, or other abrasive

methods can be swept up by the runoff of the

next rainstorm. Oils, grease, solvents, paint

drippings, and fuel spilled or dripped onto the

ground can also be carried away in the runoff.

Unless the runoff is controlled or treated in some

manner, all of these pollutants end up in the

marina basin, where they create unsightly surface

films or float until they adhere to surfaces like

boat hulls or docks. Some of these pollutants flow

dissolved in runoff or attached to soil carried by

the runoff. When they reach the marina basin,

they sink with the soil to the bottom, are eaten by

bottom-feeding fish or by filter-feeding shellfish,

or settle onto the leaves of aquatic vegetation and

clog their pores. Storm water that is treated in

some way to remove these pollutants before they

can reach the marina basin does not result in

these problems.

The National Pollutant Discharge Elimination

System (NPDES) was established to control

pollutant discharges to the nation’s waters,

including those from storm water runoff. The

1987 amendments to the Clean Water Act

mandated EPA to develop a tiered implementation

strategy for the NPDES Storm Water Program.

In response to the 1987 Amendments, EPA

developed Phase I of the NPDES Storm Water

Program in 1990. Phase I requires NPDES

permits for storm water discharges from

• “Medium” and “large” municipal separate

storm sewer systems (MS4s) that serve or

are located in incorporated places or counties

with populations of 100,000 or more people.

• Eleven categories of industrial activity, one of

which is construction activity that disturbs 5

acres or more of land.

The 11 categories of industrial activities for which

storm water discharge permits are required are

defined at 40 CFR 122.26(b)(14). A permit is

required for Standard Industrial Classification

(SIC) codes 4493 (marinas) and 3732 (boatyards

and boat builders that repair, clean, and/or fuel

boats). Note that the North American Industry

Classification System (NAICS) is replacing the

U.S. SIC system and is scheduled to be completed by 2002. NAICS was developed jointly by

the United States, Canada, and Mexico to provide

new comparability in statistics about business

activity across North America. NAICS numbers

corresponding to the previous SIC numbers are

provided in Table 4-2.
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The second phase, known as Storm Water Phase

II, was signed by EPA in October 1999 and

published in the Federal Register on December

8, 1999. The Phase II Rule will bring many

municipal separate storm sewer systems serving

fewer than 100,000 people, census districts in

counties with population densities greater than

1,000 per square mile, and small construction sites

of between 1 and 5 acres into the NPDES

permitting program by March 2003. Construction

sites where more than 1 acre is disturbed will

need to obtain a permit and implement BMPs to

minimize erosion and pollutant runoff. The rule

exempts from regulation facilities that have

industrial materials or activities that are not

exposed to rain or snow. The Storm Water Rule

and further information on Phases I and II of the

Storm Water Program can be obtained from

EPA’s web site for the point source permitting

program: http://cfpub1.epa.gov/npdes.

Removal of TSS at the 80 percent level is practicable, and the management practices mentioned

here, or combinations of them, can achieve this

degree of pollutant removal if they are designed

properly and the site is suitable for their installation

and use. The 80 percent level also provides a high

degree of protection for surface waters. Used

properly, pollutant removal management practices

can also reduce final TSS concentrations in runoff

very effectively. Table 4-3 reviews the pollutant

removal efficiencies of many storm water control

practices. Tables in Appendix F compare the

advantages and disadvantages of many storm

water control practices and their costs.

The 80 percent removal of TSS is recommended

for hull and engine maintenance areas, the runoff

from which often contains higher levels of toxic

pollutants than runoff from other parts of a marina

property. Pollutants in runoff from the remaining

marina property should be considered when

designing an effective runoff pollution prevention

system. If sufficient land area is not available

on-site to install runoff systems, management

practices that increase vegetative cover, reduce

impervious surfaces, and include infiltration

devices are practical solutions.

The principal pollutants in runoff from marina

parking areas and hull maintenance areas are

suspended solids (paint chips, sanding dust, and

the like.) and organics (predominately oil and

grease). Toxic metals (in antifoulant paints) from

boat hull scraping and sanding tend to attach

themselves to suspended soil particles and are

carried to the marina basin with the particles.

Designing and operating a hull maintenance work

area with a focus on pollution prevention is an

excellent way to prevent dangerous pollutants

from reaching the marina basin. Particularly

effective practices are designating a specified

area that has an impervious surface (cement, for

example) for hull maintenance work; doing all hull

maintenance work under a roof to prevent the

area from getting wet; and channeling and

draining runoff from other areas of the marina

property away from hull maintenance areas so it

won’t pick up the pollutants associated with hull

maintenance. Devices with controls that collect

pollutants as they are produced, such as vacuumbased (or dustless) sanders, are also effective for

preventing pollutants from entering runoff.

Pollutants can also be trapped, collected, or

filtered after they are on the ground but before it

rains. This can be accomplished by using street

Table 4-2. Conversion of SIC to NAICS.
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Table 4-3. Effectiveness of management practices for runoff control (adapted from Caraco and Winer, 2000).

Shaded rows show data for groups of practices (e.g., dry ponds includes quality control ponds and dry extended detention

ponds).

Numbers in italics are based on fewer than five data points.

a

 Excludes vertical sand filters

b

 Refers to open channel practices not designed for water quality.

TSS = total suspended solids, TP = total phosphorus, OP = ortho-phosphorus, TN = total nitrogen, NOx = nitrate and nitrite

nitrogen, Cu = copper, Zn = zinc.
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sweepers and vacuums that collect debris from

the ground, placing tarps under boats while they

are being sanded or painted, and planting grass

buffers around hull maintenance areas, parking

lots, sidewalks, and other impervious surfaces

where pollutants tend to accumulate. Grass

buffers effectively filter runoff water before it

reaches surface waters, and they are attractive

landscape elements.

Covering areas that are not used for boat maintenance with a porous surface allows rainwater to

filter into the ground and reduces the amount of

runoff created on the marina property. Crushed

gravel or concrete and low grassy areas interspersed around and within otherwise impervious

areas (parking lots, for example) are surfaces that

allow rainwater to infiltrate into the ground.

Directing storm water to a grassed area instead

of to drains, pipes, or cement channels is an

effective way to prevent the pollutants in runoff

from reaching the marina basin, regardless of

whether the runoff originates from parking lots,

hull maintenance areas, rooftops, or any other

impervious surface.

Some marinas might need to pretreat storm water

runoff before it is discharged to a local sewer

system. Pretreating wastewater from hull cleaning (pressure washing) might also be needed. The

state or local environmental agency should be

contacted to determine any specific legal requirements for treatment before discharge.

The goal of 80 percent reduction in the load of

total suspended solids (TSS) in storm water runoff

recommended in this management measure is

achieved by eliminating (by pollution prevention or

source reduction) 80 percent of the total annual

load of suspended materials produced in an

average year of work. Most marinas use some

management practices and are already collecting

some or all of this 80 percent. Note that 80 percent

of the TSS load cannot usually be eliminated during

each storm because the efficiency of any means

chosen to remove pollutants from storm water

fluctuates above and below 80 percent for

individual storms. The goal of the management

measure is to control an average of 80 percent of

the amount of TSS produced at a marina during

any given year. Because no two marinas are the

same, the storm water control management

practices used to achieve this goal have to be

chosen site-specifically for each marina.

The annual TSS load baseline can be calculated

as follows:

• Assume that marina operations are being

conducted as usual, except that no management practices are used to collect pollutants

from hull maintenance areas. All of the

sanding dust, paint chips, and so forth produced fall to the ground.

• Given this scenario, add together the total

amount of solid pollutants, such as paint chips

and sanding dust, that would be swept away

in runoff during storms that occur over a

1-year period and that are less than or equal

to the 2-year/24-hour storm for the area.

Solids carried away in snowmelt runoff should

also be included.

• Multiply this quantity by 80 percent (0.80) to

obtain the target minimum quantity of solid

pollutants to be removed from storm water

runoff and prevented from reaching the

marina basin or storm drain.

This calculation can be complicated, primarily

because of the difficulty in measuring the quantity

of pollutants produced at a marina. The state or

local environmental agency can be contacted for

additional storm water guidance and for information pertaining to storm water regulations.

Applicability

This management measure is applicable to new

and expanding marinas and to existing marinas at

a minimum at hull maintenance areas.

Best Management Practices

♦ Perform as much boat repair and

maintenance work as possible inside work

buildings.

Sandblasting is best performed in a place where

the debris produced is prevented from drifting to

surrounding areas and being swept away in storm

water runoff. One of the simplest and most

effective ways to prevent pollutants from boat

repairs from entering storm water runoff is to
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perform as much work as possible under roofs or

in enclosures. Performing maintenance work in a

fully enclosed building protects the work area

from wind and contains the dust and debris

produced during the work so it is much easier to

clean up afterward.

♦ Where an inside work space is not available, perform abrasive blasting and sanding within spray booths or tarp enclosures.

The inside of a building provides the most protected space, but if a large enough interior space

is not available, a suitably sized area can be

protected with tarps or temporary plastic buildings

can be used. Tarps help prevent residue from

drifting to nonwork areas of the marina and into

surface waters. Scheduling work on calm days

helps ensure that wind won’t carry debris and

pollutants to other areas of the marina property

and the marina basin.

♦ Where buildings or enclosed areas are not

available, provide clearly designated land

areas for boat repair and maintenance.

If a facility is large enough, one or more sections

of the yard, ideally located well away from the

shore, can be designated for boat repairs and

maintenance (Figure 4-8). Mark the area well

with signs, post a list of boat owner responsibilities, indicate the rules for use of the work area,

and do not permit work outside the designated

areas. Areas where abrasive work will be

performed should be protected from wind and

enclosed if possible. This practice should help the

marina property stay relatively clean. Where

possible, inland areas, away from surface waters,

should be used for boat repair work.

♦ Design hull maintenance areas to minimize

contaminated runoff.

Hull maintenance areas can be located indoors or

outdoors, and activities that produce a large

amount of polluting debris can be conducted over

a dry, impervious surface like a cement pad.

Other portable, temporary ground covers like

tarps can also be effective. Such a surface makes

it easy to collect and properly dispose of debris,

residues, solvents, and spills before they enter

storm water runoff.

♦ Use vacuum sanders both to remove paint

from hulls and to collect paint dust and

chips.

Vacuum sanders have proven very effective at

capturing paint dust and chips during boat hull and

bottom sanding. Immediate capture prevents paint

dust and chips from entering the marina basin,

makes cleaning up the work area easier. It also

increases the speed at which a boat bottom can

be completely sanded.

Such sanders capture up to 98 percent of the dust

generated. Workers do not have to wear full suits

with respirators. They use fewer disk pads and

have less cleanup to perform in surrounding

areas. Vacuum-based sanders are increasingly

being used in boatyards and marinas, and they

might be available for rental by boat owners who

want to sand their own hulls. Many marinas have

converted to dustless sanders and require that

they be used by customers and outside contractors. In addition to preventing pollution, using

vacuum sanders can dramatically increase the

efficiency of sanding operations.

The results of a BMP demonstration project at

five Rhode Island marinas showed that several

techniques can make the use of vacuum sanders

more effective. First, the availability of the

machinery needs to be publicized with flyers or

Figure 4-8. Conanicut Marine Service (Rhode Island)

found that purchasing land almost a mile from the

shore and using a hydraulic boat trailer was

significantly less expensive than purchasing

waterfront property, and doing so allowed expansion

of its service work to an inland boatyard. No coastal

permits were needed for the inland yard, and the risk

of water pollution from runoff from the yard was

significantly reduced (USEPA, 1996: Clean Marinas—

Clear Value).
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signs in hull maintenance areas. Second, staff

should be well trained and ready to inform

customers that a professional vacuum sander is

available for use and how to use it properly. Users

need to be given complete operating instructions

and must clearly understand them before using

the machine.

♦ Restrict the types and/or amount of do-ityourself work done at the marina.

Largely for environmental liability reasons, an

increasing number of marina owners are restricting do-it-yourself boat repair work of the “dirty”

kind, such as exterior sanding and painting. A

small but increasing percent of marinas are

prohibiting such repairs on-site unless done by a

professional who is trained in, understands, and

follows state-approved environmental management practices.

♦ Clean hull maintenance areas immediately

after any maintenance to remove debris,

and dispose of collected material properly.

Cleaning hull maintenance areas immediately

after maintenance or repair work is done removes

trash, visible paint chips, and other debris before

they can be blown or washed into the marina

basin. Spent sandblasting grit, boat repair debris,

and solid waste should be stored under cover and

in a manner that minimizes contact with process

or storm water. Vacuuming or sweeping is an

excellent method of collecting these wastes,

especially over paved surfaces. Hosing a maintenance area for cleanup can result in the same

pollution that storm water would cause.

♦ Capture and filter pollutants out of runoff

water with permeable tarps, screens, and

filter cloths.

Tarpaulins can be placed on the ground, before a

boat is placed in a cradle or stand for sanding and

painting. The common plastic tarpaulins collect

paint chips, sanding dust, and paint drippings,

which then can be collected and disposed of into

dumpsters with other solid trash, as permitted by

local or state ordinances. Impermeable plastic

tarps, however, have their drawbacks. Wind easily

blows dust and chips off the tarps, and rainwater

washes debris from the tarps. Semipermeable

filter cloths can be more effective than solid cloth

or plastic tarps for collecting debris where wind is

a problem, where tarps are not always cleaned

each day after work is completed, or where work

is continued during light rains. The filter cloths

hold onto debris better and allow water to pass

through while retaining debris for later disposal.

♦ Sweep or vacuum around hull maintenance

areas, roads, and driveways frequently.

Frequent vacuuming of impervious areas can

effectively prevent pollutants from reaching the

marina basin and nonmaintenance areas of the

marina property. Scheduling vacuuming (e.g.,

once a day or every other day during the boating

season) and adhering to the schedule helps make

this a particularly effective management practice.

The practice is most effective in hull maintenance

areas if the surface under any boat being worked

on is swept at the end of each workday.

♦ Sweep parking lots regularly.

Cars, trucks, commercial vehicles, and foot traffic

carry a lot of sand, grit, and dirt to parking lots.

Gum wrappers, paper and styrofoam cups,

cigarette butts, and cellophane wrappings tend to

end up on parking lot pavement as well. Storm

water carries these pollutants to the marina basin

or to drain inlets, catch basins, and oil/grit separators. Regular parking lot sweeping helps reduce

the amount of sand, grit, and trash that reaches

the marina basin and storm water controls.

Because catch basins and oil/grit separators

require periodic cleaning for efficient operation,

sweeping the parking lot extends the time

between sweepings.

♦ Plant grass between impervious areas and

the marina basin.

Grass retains and filters pollutants from runoff. A

well-maintained lawn that is located between

impervious surfaces (e.g., parking lots) and the

marina basin and to which runoff from the

impervious surface is directed increases rainwater

infiltration and creates an attractive marina

environment (Figure 4-9).

The technical term for a channel or ditch planted

with grass and used for storm water treatment is

grassed swale. Grassed swales are low-gradient
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channels that can be used in place of buried storm

drain pipes (Figure 4.10). To effectively remove

pollutants, grassed swales need to have only a

slight slope and should be long enough to allow all

of the pollutants in storm water to be filtered out.

Because storm water is directed to them and

storms are occasionally very strong, erosionresistant vegetation such as deep-rooted grasses

works best. The vegetation filters out pollutants

and absorbs nutrients from the storm water, and

runoff infiltrates into the ground as it is slowed by

the grass in the swale. Grassed swales are best

used in conjunction with other practices listed under

this management measure.

♦ Construct new or restore former wetlands

where feasible and practical.

If space and economy permit, consider restoring

wetland vegetation that might have formerly

existed at the edge of the marina basin or altering a

portion of the basin perimeter to support wetland

vegetation. Wetlands are extremely efficient at

removing pollutants from water.

♦ Use porous pavement where feasible.

Pervious pavement has strength characteristics

approximately equal to those of traditional pavement but allows rainfall and runoff to percolate

through it. The key is the elimination of most of

the fine aggregate found in conventional pavements.

There are two types of pervious pavement, porous

asphalt and pervious concrete. Porous asphalt has

coarse aggregate held together in the asphalt with

sufficient interconnected voids to yield high

permeability. Pervious concrete, in contrast, is a

discontinuous mixture of Portland cement, coarse

aggregate, admixtures, and water that also yields

interconnected voids for the passage of air and

water. Underlying the pervious pavement are a

filter layer, a stone reservoir, and a filter fabric.

Stored runoff gradually drains out of the stone

reservoir into the subsoil.

A porous surface can also consist of a coarse,

permeable top layer covering an additional layer

of gravel (Figure 4-11). Runoff infiltrates through the

porous layer and into the ground. As storm water

passes through the pavement, the gravel, and

perhaps a perforated underground pipe system

and then into the underlying soil, pollutants are

naturally filtered out. Porous pavement helps

recharge ground water and provides excellent

pollutant removal (up to 80 percent of sediment,

trace metals, and organic matter).

Other types of porous pavements might be

suitable for walkways and areas that will not be

subjected to heavy loads.

♦ Install oil/grit separators and/or vertical

media filters to capture pollutants in runoff.

Figure 4-9. Storm water runoff is controlled at Deep

River Marina (Connecticut) by 50-foot-wide grass

buffers and a parking lot that is covered with

crushed rock and has sediment traps in the storm

drains. Picnic tables and flowers in the lawn areas

make the marina visually attractive and useful to

families. Summerfield Boat Works (Florida) added

an unpaved parking lot across the street from the

main marina property and basin and landscaped its

perimeter to blend in with the neighborhood. Harbour

Towne Marina (Florida) reduced runoff contamination

by planting a grass buffer around the perimeter of

the facility. The facility’s parking is largely paved

and drains to the buffer strip, and the grass adds a

cooling and visually pleasing element to the marina

property (USEPA, 1996: Clean Marinas—Clear

Value).
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Oil/grit separators are useful where petroleum is

spilled or could be spilled (Figure 4-12). Oil/grit

separators can be used to treat water from small

areas where other measures are infeasible. They

are particularly applicable where the work

performed contributes large loads of grease, oil,

mud, or sand to runoff. Inspection and maintenance should occur at least twice per year or per

the manufacturer’s recommendations. With

proper maintenance, oil/grit separators can last 50

years.

Vertical media filters use passive filtration to

remove many pollutants from storm water. The

pollutants removed include sediment, nutrients,

soluble metals, hydrocarbons, trash, and debris.

The filters are typically installed in high-use

parking lots, industrial parking lots, roads, bridge

decks, and multiple-use areas. A variety of filter

media can be installed to capture different

pollutants, and the number of filter media used

can be adjusted, permitting the user to adapt the

installation to the requirements of the specific

location.

♦ Use catch basins where storm water flows

to the marina basin in large pulses.

Catch basins with flow restrictions are used to

prevent large pulses of storm water from entering

the marina basin at one time. Particulates and soil

settle to the bottom of a

catch basin, in which the

bottom of the basin is typically 2 to 4 feet below the

outlet pipe (the pipe through

which the trapped water is

allowed to escape). The traps

in a catch basin require

periodic cleaning and maintenance, but if properly maintained, a catch basin should

have a life span similar to

that of oil/grit separators (50

years).

Catch basins can have a

separate chamber filled with

sand. With this design, runoff

first enters an open chamber

where coarse particles that

could clog the sand are filtered out. The runoff

then flows into a second chamber where other

pollutants are filtered out by infiltrating through

the sand. Catch basins with sand filters are

effective in highly impervious areas, where other

practices have limited usefulness. They need to

be inspected at least annually, and the top layer of

sand should be removed periodically and replaced

with fresh, clean sand.

Figure 4-10. Grassed filter strip surrounding an infiltration trence (adapted from

Schueler, 1987).

Figure 4-11. Lockwood Boat Works (New Jersey)

regraded its combined parking and boat

maintenance yard and surfaced it with 6 inches of

crushed concrete to successfully control runoff.

Using recycled concrete crushed into stone-sized

pieces, the cost was $18,000 per acre installed,

whereas crushed rock would have cost $27,000 per

acre and asphalt paving would have cost $54,000

per acre (USEPA, 1996: Clean Marinas—Clear

Value).
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4-39

♦ Add filters to storm drains that are located

near work areas.

Some storm drain designs permit insertion of a

filter to screen solid materials out of runoff. If oil

is typically contained in runoff, an oil absorption

pad can be inserted into the water pool or trap

beneath the filter as well. Filters and absorption

pads placed in storm drains must be cleaned or

replaced regularly to function properly.

♦ Place absorbents in drain inlets.

Oil and grease are not ordinarily captured by

catch basins. An absorbent material placed in a

drain where it will intercept storm water can

remove much of the oil and grease contained in

runoff. Absorbent material products can remove

10 to 25 times their weight in oil. Absorption pads

placed in drain inlets must be cleaned or replaced

regularly to function properly.

♦ Use chemical and filtration treatment

systems only where necessary.

Wastewater can be treated by the addition of

certain chemicals that cause small solid particles

to adhere together to form larger particles, which

are then filtered from the water. This type of

treatment system can remove more than 90

percent of the suspended solids and 80 percent of

most toxic metals associated with hull pressurewashing wastewater. The degree of treatment is

determined by how much of the chemical is added

and the porosity of the filter used, and it can be

altered to meet municipal standards. Because the

chemicals used for this type of treatment require

disposal themselves, this method of pollutant

removal is suggested for use only where other

methods prove ineffective. This type of treatment

system might be regulated by the state or local

environmental authority, and any regulatory

restrictions for its use should be determined

before choosing to use it.

BMP Summary Table 5 summarizes the BMPs

for Storm Water Runoff control mentioned in this

guidance.

Figure 4-12. Underground trench with oil/grit chamber (adapted from Schueler, 1987).
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