Potable Water

Our cadre of trained divers not only inspects, but repairs clearwells without taking them out of service.

We also offer other diving services: Intake inspections, clean outs, and repairs, installation/replacement of bar screens, and structural inspections.

The AWAA recommends that potable water reservoirs be cleaned at least every five years, and recommends every three years. There are good reasons for this:

Recently microorganisms capable of causing disease have been discovered in the microfilm layer of sediment in these storage reservoirs or tanks. They are not readily identifiable with current methods of detection and are not readily controlled. The only test being performed on samples taken from reservoirs is for coliforms, and most of those are negative. There is a need to know what kinds of organisms are growing in water tanks, according to a study by LiquiVision Technology, an Oregon firm that specializes in potable water services. We at Southeastern Underwater Services agree, and would like to share these with you.

Protozoa	Crustacea
Actinomycetes	Rtifers
Sulfur Bacteria	Algea
Nitrifying Bacteria	Neatodes

Some dangerous organisms that have not been addressed in literature include the bacteria Bacteroides, and Clostridium botulinum. C. botulinum in theory could live in the sediment environment of a reservoir if introduced via a dead animal.

Cleaning Potable Water Reservoirs Draining and Cleaning Compared to On-Line Using Divers

Comparison is based on ground level reservoir of one million gallons, 18 feet high by 80 feet in diameter with two inches of silt sediment on floor.

	Draining	On-Line
Cost	$4,300-$7,401	$2,700-3,100
		Cost depends on location, Multi-tank Discounts
Time	5-8 days	1 day
Loss of Service	5-8 days	None
Stress of Draining	Concrete-High	None
Cleaning Efficiency	Fair	Excellent
Damage to Coating by Cleaning	Moderate to High	None
Inconvenience	High-Compliance with OSHA Regs., Potential for Employee injury, Interruption of water, Plant routines.	None

Draining

Wasted Water. Minimum 70,000 gallons (two feet deep) to 1 million gallons. Cost range from $500 to $1,713 per million gallons.

Man power cost range: Hourly rate includes benefits, taxes, etc. Minimum $25 per hour; Maximum $45 per hour. Total manpower costs: Minimum $2,125 to maximum $3,825.

Time: 1.5 days to drain

3 days to clean, utilizing 72 man hours

1.5 days to refill, using 4 man hours

1 day contact time to disinfect using 3 man hours

1 day testing utilizing 2 man hours.