Encyclopedia of Environmental Science and Engineering, Volume I and II

PLANNING FOR NEW PROCESSES: ENVIRONMENTAL ASPECTS 995

Groundwater sampling can be conducted in conjunction

with surface water sampling. Samples are taken quarterly

from monitoring wells.

This information can then be evaluated in light of the

projected facility emissions and demands on the area’s

resources. The issues and concerns to be addressed include:

1) Use of groundwater by the plant, and the effects of

lowering water levels or pressures for this reason

or for construction purposes.

2) Changes in water quality, or effects on rocks/

deposits, caused by accidental leaks or spills, efflu-

ent discharge, slag or scrubber sludge pits, surface

water and the like. The potential impacts identi-

fied are evaluated in light of their magnitude and

importance. Extra attention is paid to those judged

significantly high in either value.

By early identification of stresses that might affect the natu-

ral systems, steps can be taken to minimize the impacts or

alleviate them to an acceptable degree. Mitigative measures

that can be taken during plant design, construction or opera-

tion, such as adding clay liners, for example, can be evaluated

and described.

Using the results of plant design, the initial impact eval-

uation and the adopted mitigative measures, a final evalua-

tion is made of the effects of the construction and operation

of the proposed plant and ancillary facilities on the natural

environmental systems.

This activity evaluates expected effects of the proposed

plant both during and after construction of the groundwater

hydrologic environment. Each effect is evaluated as to its

unavoidable adverse effects and favorable effects.

Surface Water Hydrology and Water Use

The purpose of the surface water studies is to determine,

develop and present the surface water quantity and quality

characteristics of the site and its surrounding environs. These

data and information are analyzed and evaluated in recognition

of the proposed facility’s operation and construction related

characteristics to determine and project potential effects and

impacts on the surrounding surface water. Specifically, the

objectives are:

1) To provide a quantitative description of the hydro-

logic setting of the site and its vicinity including

any stream flow characteristics (i.e., flood and low

flow frequencies, seasonal ranges, averages, and

historical extremes), and the physical and chemical

water quality characteristics of source and receiving

waters. Annual and seasonal ranges and averages

are developed.

2) To identify the other water uses (withdrawals as

well as discharges) and users including the loca-

tion and quantities involved;

3) To identify the existing water quality criteria and

regulations affecting plant discharges, and

4) To evaluate the impact of construction and opera-

tion of the proposed plant on adjacent surface

waters, with regard to the applicable water quality

criteria, and related permit requirements.

The data and information needed for the description of the

hydrologic setting of the surface waters of the site and evalu-

ation of the plant’s impact include the following:

1) Geographic and topographic maps of the site area

containing varying degrees of local and regional

details to delineate the drainage basin and its

drainage patterns.

2) Watershed characteristics such as geometry,

slope, vegetation types and density, and soil types

to derive rainfall-runoff relationships (empirical

runoff coefficient).

3) Records of rainfall events to estimate overland

flow.

4) Records of stream flows from gaging stations on

local water courses. These data are used in defin-

ing statistical stream flow characteristics.

5) Meteorological data including air temperature,

relative humidity, solar radiation, wind speed and

evaporation data, and thermal plume calculations

(as needed).

6) Records of various water users, locations of with-

drawal, quality, and quantities involved.

7) Proposed plant site location map, grade elevation,

drainage pattern, character of soil types, and cover.

8) The physical and chemical water quality charac-

teristics of the surrounding surface waters.

9) The facility description and operational characteris-

tics relating to the discharge quantity and quality. In

addition, construction procedures, methods, sched-

ules, and erosion control features are needed.

In addition to a water quality characterization program, the

required data is collected through existing sources. This

would involve a thorough search, review, and compilation

of the existing hydrological data base. Appropriate Federal,

State, and local agencies are contacted and interviewed and

published regulatory materials is reviewed to gain informa-

tion regarding other water users and water laws affecting the

plant construction and operation.

A field monitoring program is carried out to obtain water

quality characteristics of intake and discharge waters. Water

quality samples are taken quarterly from selected stations.

A hydrological assessment of the construction phase is

undertaken to:

1) identify changes in drainage patterns and possible

effects on flooding potential,

2) identify changes in riparian terrestrial habitat areas,

3) identify the potential for erosion and local soil

losses.

These impact areas are addressed, and mitigating measures

are specified for their control.

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