SECTION 4: Management Measures

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4.2. WATER QUALITY ASSESSMENT

Management Measure for Water Quality Assessment:

Assess water quality as part of marina siting and design.

Management Measure Description

Water quality can be assessed as a part of new

marina development or expansion. This management measure is useful for determining the

suitability of a location for marina development,

the best marina design for ensuring good water

quality, and the causes and sources of water

quality problems.

When planning for a new or expanded marina

site, state water quality management agencies can

be contacted for available information. A water

quality assessment consists of taking samples of

water from a waterbody; testing them for one or

more criteria, usually chemical and physical

characteristics and the presence of pathogenic

organisms; and comparing the results to accepted

standards of water quality. Historically, state

water quality assessments have focused on

testing the dissolved oxygen concentration of

water and the presence of pathogen indicators,

such as fecal coliform bacteria (Escherichia

coli) and enterococci. Other tests, such as

measurement of water temperature or Secchi disk

depth (Figure 4-3), are used as well.

The dissolved oxygen concentration in water is

used as an indicator of the general health of an

aquatic ecosystem. A good concentration of

dissolved oxygen (typically about 6 milligrams/liter

[mg/L], but “good” can vary from waterbody to

waterbody) can indicate that there’s enough

oxygen for fish to breathe and aquatic plants to

photosynthesize, and there’s a good exchange of

gases between the waterbody and the atmosphere. A low dissolved oxygen concen-tration, or

a level below what is normal for the waterbody,

might indicate that there is too much decaying

organic matter in the water or that a film of oil or

other substance is on the surface preventing an

exchange of gases with the atmosphere, either of

which could be due to nonpoint source pollution.

Pathogenic organisms in the water indicate the

potential for public health problems. Pathogens

are contained in human and animal fecal waste,

and they can cause illness. Tests for these water

quality criteria can be used to determine the

condition of a site where a marina is proposed to

be developed.

Federal, state, and municipal agencies routinely

test the water of coastal and estuarine waters,

lakes, and reservoirs, especially if there is a lot of

recreational use of the waterbody and protection

of public health is important. Results of the tests

can be obtained by calling the agency that does

the testing (e.g., state department of natural

resources or environmental protection).

Figure 4-3. The Secchi disk is a simple and useful

tool for monitoring long-term trends in water quality.
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National Management Measures Guidance

Applicability

This management measure primarily applies to the

design of new and expanding marinas.

Best Management Practices

Monitoring can serve many purposes, such as

determining the ambient quality of water, determining the extent or causes and sources of a

water quality problem, analyzing trends in water

quality, and measuring the effectiveness of

management practices used in the marina.

Modeling is appropriate for comparing the

effects of different options, such as predicting the

water quality that would result from different

marina designs before actual construction or the

effects of various marina designs on water

circulation in a marina basin before a planned

expansion. In areas of known good water quality,

monitoring might not be needed for small marina

developments. The BMPs described here are

useful for major developments or expansions so

that sufficient water quality measurements are

made at a site to ensure that existing conditions

are not significantly altered.

When considering monitoring water quality at a

marina, consider that results indicating a water

quality problem exists at a marina do not necessarily mean that the marina is the source of the

problem. Marinas often are located where their

water quality reflects other activities in a watershed, lake, or river. Determining of the source of

water quality problems often involves a watershed-wide monitoring effort. See page 1-5 for

more information about EPA’s Watershed

Approach.

♦ Use water quality sampling and/or monitoring to measure water quality conditions.

Water quality data for the waterbody on which a

marina is located might be available. Many states

or local agencies collect this information. A state

agency of environmental protection, a local or

regional water quality authority, a parks and

recreation department, USEPA, the U.S. Geological Survey, the U.S. Army Corps of Engineers, or

a local university (such as a Sea Grant college) is

potential source of water quality data.

It will be useful to contact the state agency

responsible for water quality data at the outset of

a project to establish water quality objectives and

to determine whether water quality data are

available for the site. Comparing water quality

data from the marina to water quality data

collected by a state agency, for instance, would be

best accomplished by using the same sampling

strategy and analytical methods used by the state

agency so that a comparison of the two sets of

data will be meaningful (Figure 4-4).

♦ Use a water quality modeling methodology

to predict postconstruction water quality

conditions.

Not all proposals for new or expanding marinas

will require the use of modeling techniques to

predict water quality characteristics. Numerical

modeling can be useful, however, for studying the

effects of different design alternatives and for

selecting the design that best avoids or minimizes

impacts on water quality.

Modeling techniques can be useful for predicting

flushing time and pollutant concentrations in the

absence of site-specific data. A distinct advantage of numerical models over monitoring studies

is the ability to perform sensitivity analyses. For

instance, dissolved oxygen concentrations and

flushing times can be predicted for a number of

design options once data for the marina project

have been entered into the model. Modeling can

be an expensive undertaking, and the costs should

be weighed against any anticipated benefits.

A professional marina designer would be the best

person to consult regarding the feasibility and cost

EPA Region 4 completed an in-depth

report on marina water quality. The

primary focus of the study was to provide

guidance for selecting and applying

computer models for analyzing the

potential water quality impacts (both

dissolved oxygen and pathogen indicators) of a marina. EPA reviewed a number

of available methods and classified them

into three categories—simple methods,

mid-range models, and complex models.

See Section 5.
SECTION 4: Management Measures

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of using models. Some models applicable to

marinas are reviewed in Section 5.

♦ Monitor water quality using indicators.

Water sampling, water quality monitoring, and

numerical modeling are not necessary in many

cases to gather information about the health of a

marina’s waters. Simple yet effective forms of

monitoring that provide valuable information about

the conditions in the water can be done by

someone knowledgeable of the marina and the

surrounding waterbody. Visual inspections of the

abundance and appearance of aquatic plants in

and around the marina, use of the marina and

surroundings by ducks and geese, the appearance

of bottom sediments, the general clarity of the

water near docks, and the abundance of fish can

provide all the information necessary to judge the

health of the water (Figure 4-5). All of these

characteristics are indicators of the health of the

waters. These types of inspections can be done

during the course of daily operations by any

member of the marina staff at minimal cost to the

marina. (See volunteer monitoring BMP below.)

Done every year, these visual inspections lead to

a good knowledge of the “normal” conditions in

the marina and surrounding waterbody, and any

changes will be apparent to the keen observer.

When changes are noted, some limited water

sampling can be done to determine what might

account for them if a local or state environmental

management authority hasn’t already done this.

♦ Use rapid bioassessment techniques to

monitor water quality.

Rapid bioassessment techniques can provide a

cost-effective means to assess potential sites for

marina development and to assess water quality in

an existing marina basin. This technique is

discussed further under the Habitat Assessment

management measure.

♦ Establish a volunteer monitoring program.

Marinas can help involve their clientele and local

community in water quality issues and environmental protection at the marina by beginning a

volunteer monitoring program. Across the country,

private citizens are learning about water quality

issues and helping protect the Nation’s water

resources by becoming volunteer monitors.

Volunteers analyze water samples for dissolved

oxygen, nutrients, pH, temperature, and a host of

other water constituents; evaluate the health of

stream habitats and aquatic biological communities; inventory streamside conditions and land uses

in a watershed that might affect water quality;

catalog and collect beach debris; and restore

degraded habitats.

EPA’s Office of Water encourages citizens to

learn about their water resources and supports

volunteer monitoring because of its many benefits.

Volunteer monitors build awareness of pollution

problems, become trained in pollution prevention,

help clean up problem sites, provide data for

waters that might otherwise be unassessed, and

increase the amount of water quality information

available. Among the uses of volunteer data are

delineating and characterizing watersheds,

screening for water quality problems, and measuring baseline conditions and trends.

For more information, contact EPA’s Office of

Wetlands, Oceans, and Watersheds, Monitoring

Branch, or the monitoring branch of a regional

EPA or state environmental protection office.

EPA’s volunteer monitoring Web site is located at

<www.epa.gov/owow/monitoring/vol.html>.

Figure 4-4. Cedar Island Marina (Connecticut)

scallop monitoring. After the state of Connecticut

declined a permit for expansion on the grounds that it

would result in “destroying valuable marina life and

habitat,” the marina began a program of water quality

monitoring to prove the state wrong. The marina

monitors temperature, salinity, dissolved oxygen,

habitat, coastal birds, finfish, and scallop growth.

The photo shows marina personnel checking scallop

cages suspended below the docks. The marina has

found better dissolved oxygen levels and lower fecal

coliform bacteria counts than those reported for the

town beach, and heavy metals do not accumulate in

scallops grown at the marina (USEPA, 1996: Clean

Marinas—Clear Value).
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National Management Measures Guidance

BMP Summary Table 2 summarizes the BMPs

for Water Quality Assessment mentioned in this

guidance.

Figure 4-5. Biological assemblages used for lake monitoring.
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