Lin S.D. Water and Wastewater Calculations Manual

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l. Adverse effects on wetlands and related resources

m. Feasible alternatives to proposed project

n. Other necessary mitigative measures requirements

5.5 Phase 2: Implementation

A Phase 1 D/F study identifies the major problems in a lake and rec-

ommends a management plan. Under the CLP, if funds are available,

the plan can then be implemented and intensive monitoring of the lake

and tributaries conducted either by the state EPA or a contracted

agency.

The physical, chemical, and biological parameters monitored and the

frequencies of monitoring are similar to those for Phase 1 D/F study (or

more specific, depending on the objectives). One year of water quality

monitoring is required for post-implementation study. Non-federal cost-

share (50%) funds are usually provided by state and local landowners.

A comprehensive monitoring program should be conducted to obtain

post-implementation data for comparison with pre-implementation

(Phase 1) data.

The implementation program may include keeping point- and

nonpoint-source pollutants from entering a lake, implementing in-lake

restoration measures to improve lake water quality, a monitoring

program, environmental impact and cost evaluation, and public

participation.

5.6 Phase 3: Post-restoration monitoring

The CLP has recently begun setting up a system for managing and

evaluating lake project data, designed to derive benefit from past proj-

ects. Quantitative scientific data on long-term project effectiveness

will become increasingly available through post-restoration monitor-

ing studies being conducted under Phase 3 CLP grants instituted in

1989.

Several years after Phase 2 implementation, a lake may be selected

for Phase 3 post-restoration monitoring with matching funds. For Phase 3

monitoring, the water quality parameters monitored and the frequency

of sampling in the lake and tributaries are similar to that for Phases 1

and 2. However, the period of monitoring for Phase 3 is generally 3

years with a total project period of 4 to 5 years. The purpose is to build

upon an extensive database of information gathered under Phases 1 and

2 investigations.

Data gathered from Phase 1 are compared with Phases 2 and 3 data-

bases to determine the long-term effectiveness of watershed protection

Lakes and Reservoirs 145

measures and in-lake management techniques implemented during and

since Phase 2 completion.

5.7 Watershed protection approach

The watershed protection approach (WPA) is an integrated strategy for

more effective restoration and protection of aquatic ecosystems and

human health; i.e. drinking water supplies and fish consumption

(US EPA, 1993). The WPA focuses on hydrologically defined drainage

basins (“watersheds”) rather than on areas arbitrarily defined by polit-

ical boundaries. Local decisions on the scale of geographic units consider

many factors including the ecological structure of the basin, the hydro-

logic factors of groundwaters, the economic lake uses, the type and scope

of pollution problems, and the level of resources available for protection

and restoration projects (US EPA, 1991, 1993).

The WPA has three major principles (US EPA, 1991, 1993):

1. Problem identification—identify the primary risk to human health

and ecosystem within the watershed;

2. Stakeholder involvement—involve all parties most likely to be con-

cerned or most able to take action for solution;

3. Integrated actions—take corrective actions in a manner that pro-

vides solutions and evaluates results.

The WPA is not a new program, and any watershed planning is not

mandated by federal law. It is a flexible framework to achieve maximum

efficiency and effect by collaborative activities. Everyone—individual cit-

izens, the public and private sectors—can benefit from a WPA.

The US EPA’s goal for the WPA is to maintain and improve the health

and integrity of aquatic ecosystems using comprehensive approaches

that focus resources on the major problems facing these systems within

the watershed (US EPA, 1993).

For more than two decades, the CLP has emphasized using the water-

shed protection approach. A long-standing program policy gives greater

consideration to applicants who propose restoration and protection tech-

niques that control pollutants at the source through watershed-wide

management rather than dealing with symptoms in the lake.

5.8 In-lake monitoring

In Phase 1, 2, and 3 studies, in-lake water quality parameters that need

to be monitored generally include water temperature, dissolved oxygen,

turbidity, Secchi transparency, solids (total suspended and volatile),

conductivity, pH, alkalinity, nitrogen (ammonia, nitrite/nitrate, and

total kjeldahl), phosphorus (total and dissolved), total and fecal coliforms,

146 Chapter 2

fecal streptococci, algae, macrophytes, and macroinvertebrates. Except

for the last two parameters, samples are collected bimonthly (April to

October) and monthly (other months) for at least 1 year. At a minimum,

three stations (at the deepest, the middle, and upper locations of the

lake) are generally monitored (Lin et al., 1996, 1998).

Lake water quality standards and criteria. The comprehensive information

and data collected during Phase 1, 2, or 3 study are evaluated with

state water quality standards and state lake assessment criteria. Most

states in the United States have similar state standards and assessment

criteria. For example, Illinois generally uses the water quality stan-

dards applied to lake water listed in Table 2.1; and Illinois EPA’s lake

assessment criteria are presented in Table 2.2.

The data obtained from Phase 1, 2, and 3 of the study can be plotted

from temporal variations for each water quality parameter, as shown in

the example given in Fig. 2.4. Similarly, the historical data also can be

plotted in the same manner for comparison purposes.

Indicator bacteria (total and fecal coliforms, and fecal streptococcus)

densities in lakes and reservoirs should be evaluated in the same

manner as that given for rivers and streams in Chapter 1. The density

and moving geometric mean of FC are usually stipulated by the state’s

Lakes and Reservoirs 147

TABLE 2.2 Illinois EPA Lake Assessment Criteria

Parameter Minimal Slight Moderate High Indication

Secchi depth ⬎ 79 49–79 18–48 ⬍ 18 lake use impairment

TSS, mg/L ⬍ 5 5–15 15–25 ⬎ 25 lake use impairment

Turbidity, NTU ⬍ 3 3–7 7–15 ⬎ 15 suspended sediment

COD, mg/L ⬍ 10 10–20 20–30 ⬎ 30 organic enrichment

SOURCE: IEPA, 1987

TABLE 2.1 Illinois General Use Water Quality Standards

1. Dissolved oxygen: ⬎ 5 mg/L at any time

⬎ 6 mg/L at 16 h/24 h

2. Temperature: ⬍ 30⬚C

3. Total dissolved solids: 100 mg/L

(conductivity: 1700 ␮⍀

–1

/cm)

4. Chloride: ⬍ 500 mg/L for protection of aquatic life

5. pH: 6.5–9.0, except for natural causes

(alkalinity in Illinois lakes 20–200 mg/L as CaCO

)

6. NH

-N: ⬍ 1.5 mg/L at 20⬚C (68⬚F) and pH of 8.0

⬍ 15 mg/L under no conditions

7. NO

-N: ⬍ 10 mg/L in all waters

⬍ 1.0 mg/L in public water supply

8. Total P: ⬍ 0.05 mg/L in any lake ⬎ 8.1 ha (20 acres)

SOURCE: IEPA, 1987

bacterial quality standards. The ratio of FC/FS is used to determine the

source of pollution.

Temperature and dissolved oxygen. Water temperature and dissolved

oxygen in lake waters are usually measured at 1 ft (30 cm) and 2 ft (60 cm)

intervals. The obtained data are used to calculate values of the percent

148 Chapter 2

Figure 2.4 Temporal variations of surface water characteristics at RHA-2 (Lin et al., 1996).

Lakes and Reservoirs 149

Figure 2.5 Temperature and dissolved oxygen profiles at station 2 (Lin and Raman, 1997).

DO saturation using Eq. (1.4) or from Table 1.2. The plotted data is

shown in Fig. 2.5: observed vertical DO and temperature profiles on

selected dates at a station. Data from long-term observations can also

be depicted in Fig. 2.6 which shows the DO isopleths and isothermal

plots for a near-bottom (2 ft above the bottom station).

150

Figure 2.6 Isothermal and iso-dissolved oxygen plots for the deep stations (Lin et al., 1996).

Algae. Most algae are microscopic, free-floating plants. Some are fila-

mentous and attached ones. Algae are generally classified into four

major types: blue-greens, greens, diatoms, and flagellates. Through

their photosynthesis processes, algae use energy from sunlight and

carbon dioxide from bicarbonate sources, converting it to organic matter

and oxygen (Fig. 2.7). The removal of carbon dioxide from the water

results in an increase in pH and a decrease in alkalinity. Algae are

important sources of dissolved oxygen in water. Phytoplanktonic algae

form at the base of the aquatic food web and provide the primary source

of food for fish and other aquatic insects and animals.

Excessive growth (blooms) of algae may cause problems such as bad

taste and odor, increased color and turbidity, decreased filter run at a

water treatment plant, unsightly surface scums and esthetic problems,

and even oxygen depletion after die-off. Blue-green algae tend to cause

the worst problems. To prevent such proliferation (upset the ecological

balance), lake and watershed managers often try to reduce the amounts

of nutrients entering lake waters, which act like fertilizers in promot-

ing algal growth. Copper sulfate is frequently used for algal control, and

sometimes it is applied on a routine basis during summer months,

whether or not it is actually needed. One should try to identify the

Lakes and Reservoirs 151

Figure 2.7 Photosynthesis and its chemical processes (Illinois

State Water Survey, 1989).

( )

(

)

(

)

causes of the particular problems and then take corrective measures

selectively rather than on a shot-in-the-dark basis.

Copper sulfate (CuSO

· 5H

O) was applied in an Illinois impound-

ment at an average rate of 22 pounds per acre (lb/acre); in some lakes,

as much as 80 lb/acre was used (Illinois State Water Survey, 1989).

Frequently, much more copper sulfate is applied than necessary.

Researchers have shown that 5.4 lb of copper sulfate per acre of lake

surface (6.0 kg/ha) is sufficient to control problem-causing blue-green

algae in waters with high alkalinity (⬎40 mg/L as CaCO

). The amount

is equivalent to the rate of 1 mg/L of copper sulfate for the top 2 ft

(60 cm) of the lake surface (Illinois State Water Survey, 1989). The lit-

erature suggests that a concentration of 0.05 to 0.10 mg/L as Cu

2⫹

effective in controlling blue-green algae in pure cultures under labo-

ratory conditions.

Example 1: What is the equivalent concentration of Cu

2⫹

of 1 mg/L of copper

sulfate in water?

solution:

Example 2: Since 0.05 to 0.10 mg/L of Cu

2⫹

is needed to control blue-green

algae, what is the theoretical concentration expressed as CuSO

⭈ 5H

solution:

Answer: This is equivalent to 0.20 to 0.4 mg/L as CuSO

⭈ 5H

Note: For field application, however, a concentration of 1.0mg/L as

CuSO

⭈ 5H

O is generally suggested.

> 0.20 mg/L

Copper sulfate 5 0.05 mg/L 3

249.5

63.5

5 0.255 mg/L

5 0.255 3 1 mg/L

, mg/L

CuSO

O, mg/L

63.5

249.5

5 0.255

MW of Cu

5 63.5

5 249.5

MW of CuSO

O 5 63.5 1 32 1 16 3 4 1 5s2 1 16d

152 Chapter 2

Example 3: For a lake with 50 acres (20.2 ha), 270 lb (122 kg) of copper sul-

fate is applied. Compute the application rate in mg/L on the basis of the top

2 ft of lake surface.

solution:

Step 1. Compute the volume (V ) of the top 2 ft

V ⫽ 2 ft ⫻ 50 acres

⫽ 2 ft ⫻ 0.3048 m/ft ⫻ 50 acres ⫻ 4047 m

/acre

⫽ 123.350 m

⫽ 123.3 ⫻ 10

Step 2. Convert weight (W ) in pounds to milligrams

W ⫽ 270 lb ⫻ 453,600 mg/lb

⫽ 122.5 ⫻ 10

Step 3. Compute copper sulfate application rate

⫽ 0.994 mg/L

≅ 1.0 mg/L

Secchi disc transparency.

The Secchi disc is named after its Italian

inventor Pietro Angelo Secchi, and is a black and white round plate

used to measure water clarity. Values of Secchi disc transparency are

used to classify a lake’s trophic state.

Secchi disc visibility is a measure of a lake’s water transparency,

which suggests the depth of light penetration into a body of water (its

ability to allow sunlight to penetrate). Even though Secchi disc trans-

parency is not an actual quantitative indication of light transmission,

it provides an index for comparing similar bodies of water or the same

body of water at different times. Since changes in water color and tur-

bidity in deep lakes are generally caused by aquatic flora and fauna,

transparency is related to these entities. The euphotic zone or region of

a lake where enough sunlight penetrates to allow photosynthetic pro-

duction of oxygen by algae and aquatic plants is taken as two to three

times the Secchi disc depth (US EPA, 1980).

Suspended algae, microscopic aquatic animals, suspended matter

(silt, clay, and organic matter), and water color are factors that inter-

fere with light penetration into the water column and reduce Secchi

disc transparency. Combined with other field observations, Secchi disc

Rate 5

122.5 3 10

123.3 3 10

Lakes and Reservoirs 153

readings may furnish information on (1) suitable habitat for fish and

other aquatic life; (2) the lake’s water quality and esthetics; (3) the state

of the lake’s nutrient enrichment; and (4) problems with and potential

solutions for the lake’s water quality and recreational use impairment.

Phosphorus. The term total phosphorus (TP) represents all forms of phos-

phorus in water, both particulate and dissolved forms, and includes three

chemical types: reactive, acid-hydrolyzed, and organic. Dissolved phos-

phorus (DP) is the soluble form of TP (filterable through a 0.45-␮m filter).

Phosphorus as phosphate may occur in surface water or groundwa-

ter as a result of leaching from minerals or ores, natural processes of

degradation, or agricultural drainage. Phosphorus is an essential nutri-

ent for plant and animal growth and, like nitrogen, it passes through

cycles of decomposition and photosynthesis.

Because phosphorus is essential to the plant growth process, it has

become the focus of attention in the entire eutrophication issue. With

phosphorus being singled out as probably the most limiting nutrient and

the one most easily controlled by removal techniques, various facets of

phosphorus chemistry and biology have been extensively studied in the

natural environment. Any condition which approaches or exceeds the

limits of tolerance is said to be a limiting condition or a limiting factor.

In any ecosystem, the two aspects of interest for phosphorus dynam-

ics are phosphorus concentration and phophorus flux (concentration ⫻

flow rate) as functions of time and distance. The concentration alone

indicates the possible limitation that this nutrient can place on vege-

tative growth in the water. Phosphorus flux is a measure of the phos-

phorus transport rate at any point in flowing water.

Unlike nitrate-nitrogen, phosphorus applied to the land as a fertilizer

is held tightly to the soil. Most of the phosphorus carried into streams and

lakes from runoff over cropland will be in the particulate form adsorbed

to soil particles. On the other hand, the major portion of phosphate-

phosphorus emitted from municipal sewer systems is in a dissolved form.

This is also true of phosphorus generated from anaerobic degradation of

organic matter in the lake bottom. Consequently, the form of phosphorus,

namely, particulate or dissolved, is indicative of its source to a certain

extent. Other sources of dissolved phosphorus in the lake water may

include the decomposition of aquatic plants and animals. Dissolved phos-

phorus is readily available for algae and macrophyte growth. However,

the DP concentration can vary widely over short periods of time as plants

take up and release this nutrient. Therefore, TP in lake water is the more

commonly used indicator of a lake’s nutrient status.

From his experience with Wisconsin lakes, Sawyer (1952) concluded

that aquatic blooms are likely to develop in lakes during summer months

when concentrations of inorganic nitrogen and inorganic phosphorus

154 Chapter 2