A. 
Tests shall be made on all sections of pipe throughout the entire project and shall be conducted only in the presence of the Service District or its authorized agent. Tests shall be made between adjacent valves.
B. 
Care shall be taken to insure that the entire test run of pipe is securely braced and blocked against thrust when pressure is applied. All thrust blocks must be completely set and approved. All pipe must be firmly supported and weighted down by partial backfill soil on top.
C. 
All water for testing purposes shall be potable water and procured and paid for by the owner or developer or his contractor. Prior to testing, the pipe shall be filled slowly and carefully with water from the nearest practical source, or by other approved methods. Under normal atmospheric pressure the pipe shall be allowed to soak for a minimum period of 24 hours. All entrapped air shall be expelled. The owner, developer or contractor shall provide all the apparatus or other accessories necessary to conduct the tests.
D. 
The completed piping shall be subjected to a hydrostatic pressure test equal to the rated working pressure of the pipe. This pressure shall be maintained for two hours. If any leaks are detected all pipe, joins, valves and fittings in the test section shall be examined.
E. 
Defective material disclosed as a consequence of the tests shall be removed and replaced by sound material at the developer's expense. Any join showing visible leakage shall be made airtight. The test shall be repeated until its results are satisfactory to the District or its authorized agent.
A. 
During the course of the work, all reasonable precautions shall be taken to protect the pipe interiors, fittings, and valves against contamination. When pipelaying is not in progress all openings in the pipe line shall be closed by watertight plugs.
B. 
The water main shall be closed and flushed prior to disinfection with a sufficient flow to produce a flushing velocity of at least 2.5 feet per second (ft/sec). Finished water shall be flushed through the system until no traces of foreign matter are visible. This water shall be discharged or wasted only at points specifically designated by the District.
C. 
The new pipe line shall be disinfected by chlorination in accordance with AWWA Specification C651. The disinfection agent of the chlorine solution shall be calcium hypochlorite granules or tablets. Liquid chlorine shall be used only when suitable equipment is available and only under direct supervision of a properly trained and equipped specialist approved by the District.
D. 
The chlorine solution at any point in the line shall have a minimum concentration of 25 parts per million (ppm) or 25 milligrams per liter (mg/l). The main shall be filled with water at a rate to ensure that the water within the main will flow at a velocity no greater than 1 ft/sec. To insure that this concentration is maintained the chlorine residual shall be measured at regular intervals in accordance with procedures described in the current edition of Standard Methods and AWWA Specification M12.
E. 
Tablet method consists of placing calcium hypochlorite granules and tablets in the water main as it is being installed and filling the main with potable water when installation is completed. This method gives an average chlorine dose of approximately 25 mg/l.
F. 
Placement of calcium hypochlorite granules shall be at the upstream end of the first section of the pipe, at the upstream end of each branch main and at 500-foot intervals. Placement is to be made during construction in accordance with the following Table 1.
WARNING: This procedure must not be used on solvent-welded plastic or on screwed joint steel pipe because of the danger of fire or explosion from the reaction of the joint compounds with the calcium hypochlorite.
Table 1
Ounces of Calcium Hypochlorite Granules To Be Placed at Beginning of Main and at Each 500-Foot Interval
Pipe Diameter
(inches)
Calcium Hypochlorite Granules
(ounces)
4
1.7
6
3.8
8
6.7
10
10.5
12
15.1
14 or larger
D2 x 15.1*
NOTES:
*
Where D is the inside diameter in feet.
Table 2
Number of 5g Hypochlorite Tablets Required for Dose of 25 mg/l*
Pipe Diameter
(inches)
Length of Pipe Section
(feet)
13 or less
18
20
30
40
4
1
1
1
1
1
6
1
1
1
2
2
8
1
2
2
3
4
10
2
3
3
4
5
12
3
4
4
6
7
16
4
6
7
10
13
NOTES:
*
Based on 3.25 g available chlorine per tablet; any portion of tablet rounded to next higher number.
G. 
Placing of calcium hypochlorite tablets. During construction, 5 g calcium hypochlorite tablets shall be placed in each section of pipe. Also, one tablet shall be placed in each hydrant, hydrant branch, and other appurtenances. The number of 5 g tablets required for each pipe section shall be 0.0012d2L rounded to the next higher integer, where "d" is the inside pipe diameter in inches, and "L" is the length of the pipe section in feet. Table 2 shows the number of tablets required for commonly used sizes of pipe. The tablets shall be attached by a food-grade adhesive. There shall be adhesive only on the broadside of the tablet attached to the surface of the pipe. Attach tablets inside and at the top of the main, with approximately equal number of tablets at each end of a given pipe length.
H. 
When installation has been completed, the main shall be filled with water at such a rate that water within the main will flow at a velocity no greater than 1 ft/sec. During disinfection all valves and hydrants shall be operated in order to disinfect the appurtenances. Precautions shall be taken to assure that air pockets are eliminated. Water shall remain in the pipe for at least 24 hours. If the water temperature is less than 41° F. (5° C.), the water shall remain in the pipe for at least 48 hours. A detectable free chlorine residual should be found at each sampling point after the twenty-four-hour period. The results must be reported.
I. 
After the specified retention period, the chlorinated water shall be flushed from the main until the residual chlorine concentration is no higher than that prevailing in the existing system or less than 0.20 part per million.
J. 
After final flushing and before the water main is placed in service, samples of water from several designated points in the line shall be collected in sterile bottles treated with sodium thiosulphate. No hose or fire hydrant shall be used in the collection of samples. The samples shall be forwarded to an approved laboratory for bacterial examination. If this examination indicates the presence of coliform organisms, the entire disinfection process shall be repeated or continued until the examination indicated two satisfactory bacteriological results taken 24 hours apart.
K. 
Pipe, taps and fittings used at connections to the existing system shall be thoroughly disinfected before installation. Excavation for such connection is completed, and extreme care shall be exercised to prevent contamination of the pipe and connection fittings. The inside of the existing pipe within three feet of the point of connection shall be disinfected by spraying with solution containing not less than 200 ppm of chlorine immediately before connection is made. If at any time the water in the existing piping becomes contaminated, this piping shall be disinfected as specified for new piping, back to the nearest gate valve or valves, or beyond those points as necessary to include all contamination piping.
L. 
The compete disinfection process and methods followed, especially if materially different from those specified, shall be in accordance with the directives of the Virginia Department of Health, and all methods employed shall meet with this approval. Definite instructions as to the collection and shipment of the samples shall be requested from the Department of Health and shall be followed explicitly. Final approval of the bacterial examination shall be received from the Department of Health prior to placing the new pipeline into operation.