No. 27658 (Amendment): R317-3-10. Lagoons

DAR File No.: 27658
Filed: 01/14/2005, 04:04
Received by: NL

 

RULE ANALYSIS

Purpose of the rule or reason for the change:

The proposed amendments are being made to bring all the R317 rules into conformity with the changing from "Total Coliform" or "Fecal Coliform" bacteria to "E. coli" in Rule R317-2 entitled Standards of Quality for Waters of the State. (DAR NOTE: The proposed amendment to Rule R317-2 was published in the January 1, 2005, issue of the Utah State Bulletin under DAR No. 27593.)

 

Summary of the rule or change:

"Total Coliform" or "Fecal Coliform" bacteria and their associated numeric criteria are changed to (or augmented with) "E. coli" and its associated numeric criteria.

 

State statutory or constitutional authorization for this rule:

Section 19-5-104

 

Anticipated cost or savings to:

the state budget:

There are no anticipated costs or savings to state budget. The proposed amendments change one method of measuring bacteria for another. The costs of the current and proposed analysis methods are substantially the same.

 

local governments:

The proposed amendments change one method of measuring bacteria for another. The costs of the current and proposed analysis methods are substantially the same. There are no anticipated costs or savings to local government.

 

other persons:

The proposed amendments change one method of measuring bacteria for another. The costs of the current and proposed analysis methods are substantially the same. There are no anticipated costs or savings to other persons.

 

Compliance costs for affected persons:

There are no anticipated additional compliance costs for affected persons. The proposed amendments change one method of measuring bacteria for another. The costs of the current and proposed analysis methods are substantially the same.

 

Comments by the department head on the fiscal impact the rule may have on businesses:

There are no anticipated additional compliance costs for affected businesses. The proposed amendments change one method of measuring bacteria for another. The costs of the current and proposed analysis methods are substantially the same.

 

The full text of this rule may be inspected, during regular business hours, at the Division of Administrative Rules, or at:

Environmental Quality
Water Quality
CANNON HEALTH BLDG
288 N 1460 W
SALT LAKE CITY UT 84116-3231

 

Direct questions regarding this rule to:

Dave Wham at the above address, by phone at 801-538-6052, by FAX at 801-538-6016, or by Internet E-mail at [e-mail]

 

Interested persons may present their views on this rule by submitting written comments to the address above no later than 5:00 p.m. on:

03/11/2005

 

Interested persons may attend a public hearing regarding this rule:

3/02/2005 at 7:00 PM, City Library, 303 N 100 E, West Room, Cedar City, UT and 3/04/2005 at 3:00 PM, Cannon Heath Building, 288 N 1460 W, Room 125, Salt Lake City, UT

 

This rule may become effective on:

04/01/2005

 

Authorized by:

Dianne R. Nielson, Executive Director

 

 

RULE TEXT

R317. Environmental Quality, Water Quality.

R317-3. Design Requirements for Wastewater Collection, Treatment and Disposal Systems.

R317-3-10. Lagoons.

10.1. Lagoon Siting

A. Distance from Habitation. A lagoon should be sited as far as practicable, with a minimum of 1/4 mile (0.4 kilometer), from areas developed for residential or commercial or institutional purposes or may be developed for such purposes within a foreseeable future. Site characteristics such as topography, prevailing wind direction, forests, etc., must be considered in siting the lagoon.

B. Prevailing Winds. The lagoon should be sited where the direction of local prevailing winds is towards uninhabited areas.

C. Surface Runoff. The lagoon should not be sited in watersheds receiving significant amounts of storm-water runoff. Storm-water runoff should be diverted around the lagoon and protect lagoon embankments from erosion.

D. Hydrology and hydrogeology. Close proximity to water supplies and other facilities subject to wastewater contamination should be avoided in siting the lagoon. A minimum separation of four (4) feet (1.2 meters) between the bottom of the lagoon and the maximum ground water elevation should be maintained.

E. Geology

1. The lagoon shall not be located in areas which may be subjected to karstification, i.e., sink holes or underground streams generally occurring in area underlain by porous limestone or dolomite or volcanic soil.

2. A minimum separation of 10 feet (3.0 meters) between the lagoon bottom and any bedrock formation is recommended.

10.2. Small Facilities. The executive secretary will review and approve the construction of a lagoon for a design rate of flow less than 25,000 gallons per day (95 cubic meters per day) only if:

A. there are no other alternatives for wastewater treatment and disposal available to the applicant;

B. there is no other appropriate technology for wastewater treatment and disposal except lagoon; and

C. the applicant has resources to satisfactorily operate and maintain the lagoon.

10.3. Basis of Design. Design variables such as lagoon depth, number of units, detention time, and additional treatment units must be based on effluent standards for BOD₅, total suspended solids (TSS), [fecal coliforms]E. coli, dissolved oxygen (DO), and pH.

A. Design for Discharging and Total Containment Lagoons

1. The design shall be based on BOD₅ loading ranging from 15 to 35 pounds per acre per day (16.8-39.2 kilograms per hectare per day).

2. The design for total containment lagoons shall be based on conservative estimates of precipitation, evaporation, seepage or percolation and inflow relevant to the site. A mass diagram showing each of the foregoing factors on a month-by-month basis, shall be prepared and submitted with the design and plans for review.

B. Design Depth. The minimum operating depth should be such that growth of aquatic plants is suppressed to prevent damage to the dikes, bottom, control structures, aeration equipment and other appurtenances.

1. Discharging or Total Containment Lagoons. The maximum water depth shall be 6 feet (1.8 meters) in primary cells. Greater depth in subsequent cells may be deeper than 6 feet provided that supplemental aeration or mixing is incorporated in the design. Minimum operating depth shall be three feet.

2. Aerated Lagoons. The design water depth should range from 10 to 15 feet (three to 4.5 meters). The type of the aeration equipment, waste strength and climatic conditions affect the selection of the design water depth.

3. Sludge Accumulation. The minimum depth of 18 inches (45 centimeters) for sludge accumulation shall be provided in primary cells of facultative lagoons.

C. Freeboard. The minimum freeboard shall be three (3) feet (1.0 meter). For small systems - less than 50,000 gallons per day (190 cubic meters per day), the minimum freeboard can be reduced to two (2) feet (0.6 meter).

D. Slope

1. Maximum Dike Slope. The inner and outer dike slopes shall not be steeper than 3 horizontal to 1 vertical (3:1).

2. Minimum Dike Slope. Inner dike slope shall not be flatter than 4 horizontal to 1 vertical (4:1). A flatter slope can be specified for larger installations because of wave action, but have the disadvantages of added shallow areas, that are conducive to emergent vegetation.

E. Seepage

1. The bottom of lagoons treating domestic sewage shall be no less than 12-inch (30 centimeters) in thickness, constructed in two six-inch (15 centimeters) lifts. The selection of the type of seals using soils, bentonite, or synthetic liners for the lagoon bottom shall be based on the design hydraulic conductivity, durability, and integrity of the proposed material.

2. Hydraulic conductivity of the lagoon bottom as constructed or installed, shall be such that it meets the requirements of ground water discharge permit issued under R317-6, (Ground Water Quality Protection rules). It shall not exceed 1.0 x 10^-6 centimeters per second.

3. The seepage loss may vary with the thickness of the bottom seal and hydraulic head thereon. Detailed calculations on the determination of seepage loss shall be submitted with the design. It shall not exceed 6,500 gallons per acre per day (60.8 cubic meters per hectare per day).

4. Results of field and laboratory hydraulic conductivity tests, including a correlation between them, shall meet the design and ground water discharge permitting requirements, before the use of lagoon can be authorized.

5. Hydraulic conductivity for the lagoon where industrial waste is a significant component of sewage, shall be based on ground water protection criteria contained in R317-6 (Ground Water Quality Protection rules).

F. Detention time

1. Discharging Lagoons. Detention time in the lagoon shall be the greater, and exclusive of the capacity provided for sludge build-up, of:

a. 120 days based on winter flow and the maximum operating depth of the entire system; or

b. 60 days based on summer flow and peak monthly infiltration/inflow.

c. The detention time shall not be less than 150 days at the mean operating depth for effluent discharge without chlorination. In order to meet bacteriologic standards in such a case, at least 5 cells shall be provided. The detention time and organic loading rate shall depend on climatic or stream conditions.

2. Aerated Lagoons

a. The detention time shall be the greater of:

(1) 30 days minimum; or

(2) the value determined using the following formula: E = (1/(1 + (2.3 x K₁ x t))) where: t = detention time, days; E = fraction of BOD₅ remaining in an aerated lagoon; K_l = reaction coefficient, aerated lagoon, base 10. For normal domestic sewage, the K₁ value may be assumed to be 0.12 day^-1 at 20 degrees Centigrade, and 0.06 day^-1 at one degree Centigrade.

b. The reaction rate coefficient for domestic sewage which includes some industrial wastes must be determined experimentally for various conditions which might be encountered in the aerated lagoons. The reaction rate coefficient based on temperature used in the experimental data, shall be adjusted for the minimum sewage temperature.

G. Aeration Requirements for Aerated Lagoons

1. The design parameters for the aerated lagoon should be based on pilot testing or validated experimental data.

2. When pilot testing is not conducted, the design should be based on two pounds of oxygen input per pound of BOD₅ applied (two kilograms of oxygen input per kilogram of BOD₅ applied). However, it may vary with the degree of treatment, and the concentration of suspended solids to be maintained. A tapered mode of aeration is permitted based on applied BOD₅ to each cell.

3. Aeration equipment shall be capable of maintaining a minimum dissolved oxygen level of 2 milligrams per liter in the lagoon at all times such that their circles of influence meet.

a. Circle of Influence. It is that area in which return velocity is greater than 0.15 feet per second as indicated by the manufacturer's certified data. Table R317-3-10.3(G)(3)(a) may be used when the manufacturer's certified data is not available.

b. Freezing. Suitable protection from weather shall be provided for aerators and electrical controls.

H. Industrial Wastes. For industrial waste treatment using lagoon, the design parameters shall be based on the type and treatability of industrial wastes using biological processes. In some cases it may be necessary to pretreat industrial waste or combine with domestic sewage.

 

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KEY: wastewater, water quality, water pollution

[August 4, 1995]2005

Notice of Continuation October 7, 2002

19-5

19-5-104

40 CFR 503