RCC underground sumps Vs. Composite underground Treated water storage tanks
RCC underground sumps Composite underground Treated water storage Tank (COMPTNK)
Seepage of water: When the soil is settling down, RCC structure gets crack, resulting seepage of drinking water in to soil and sewage into the sump, resulting contamination of the drinking water. Seepage of Water: COMPTNK is factory made; it never allows percolation of even moisture from outside or into tank since the material is homogeneous unlike concrete which is heterogeneous. Thus seepage of either drinking water or sewage is not possible.
Loss by evaporation: A very good RCC tank, well constructed with water sealing compounds etc., will still render a loss of 3% due to evaporation by capillary action. Loss by Evaporation: As COMPTNK is molded plastic; it is not a heat conductor. So evaporation of water is prevented.
Construction: Long duration (45 days or more) for construction and curing. Construction: Can be installed in one day and commissioned the same day.
Corrosion: If the tank is constructed in the salty water ground, where reinforced steel bars react with the salt and corroded. In this case, the RCC structure is getting weak and its life is drastically reduced resulting, new tank is to construct in short span of life. During monsoon or when the ground water table is high, quality of construction is affected very badly since the reinforcement is exposed to ground water as well as the stored water, resulting reinforced steel rods are getting corroded within a short span of time. Once reinforcement gets weakened the tank well collapses requiring rework time, again delaying the construction. Corrosion: COMPTNK constructed composite material (no reinforcement steel). It is having the good corrosion resistance property in all type of water. It is inert in salty water & it can withstand saline atmosphere as well. However, there is no issue on reinforced steel bars and its life. The tank can be installed even during monsoon and water saturated soil.
Imperviousness: RCC tank is not impervious. Ground water percolates into the tank affecting the quality of stored water rendering turbidity and increase in TDS level, weed growth and bacteria. Imperviousness: COMPTNK is impervious. Ground water never enters into the tank and not contaminating the quality of stored water.
Construction quality: The strength of the RCC Tank is solely dependent on the workmanship of masons. Quality of construction is unequal, may vary depends upon the masons and site to site. Construction quality: COMPTNK are factory made, pressure / hydro tested as per ASTM (American Society for Testing of materials) D 4097 standards and dispatched to site and hence we stand to gain full value for money spent.
Algae growth: Growth of algae and other types of bio-fouling is very easy, since the RCC wall will act as membrane between treated water and earth. Algae growth: Cleaning of tank is very simple through pumping of dosing chemical. Scrubbing of walls is not necessary since tank inside is smooth and does not allow any precipitation in the tank wall. Hence growth of algae and other type of Bio-fouling considerably eliminated.
Improper concrete slabs: Will allow frogs and water snakes to the sump. Mechanically tight cover: will never allow frogs, water snakes and other unwanted elements to the tank.
Volume of space: Considering the wall thickness of 250 mm, RCC tank requires a volume of 16.2 M3 to store water of volume of 12 M3 (volume occupied by the civil material is 4.26 M3) which is 35% higher than the CUST. Volume of space: CUST can be tailor made to suit specific dimensions. Volume of space required is much less than RCC tank. The volume occupied by the CUWST is hardly 5% more than the water stored. This aspect is very crucial in areas particularly cities having acute space restriction problem.
Additional advantages:

1. Tanks are designed specifically to store the water capacity of 13500 litres, having the weight of 700 kgs; it also can be used as overhead tank.

2. Since the tank can be shifted from one place to another (while carrying out renovations / modifications to the building), it is having resale value.

3. CUST can be supplied with inside partitions to meet the specific needs of the clients.

4. The outer diameter of the tank is 2300 mm, suitable for transporting by commercial vehicles.

5. The design life of the tank is 50 years.

6. The tank is designed to be buried with soil cover of up to 1.5 meters and be installed to counter the buoyancy is fully saturated soil condition.