Bali water tank & piping

Water tanks and piping

In this Island is still possible to find very poor quality storage tank.

Check it in your house or your hotel.

The funny thing is that many privates are now installing high quality SS or food grade plastic, but many public places still have concrete open tank.

Open means that they have a simple cover, sometimes in asbestos that allow all the possible contamination. (are exposed to cats, monkeys, insects, reptiles, dust and airborne contamination.

Water Quality Problems With Tanks And Cisterns

All water, even high quality treated potable water, will deteriorate in water storage tanks and cisterns. The longer the time in storage, the greater the potential for change. Some types of changes are:

• loss of disinfection residual by chlorine depletion, resulting in microbial re-growth and contamination;
• increasing concentrations of oxidized minerals and organic matter; chlorine reacts with organic and inorganic matter (e.g. iron, manganese, calcium, magnesium, hydrogen sulphide, dissolved organic carbon, etc.);
• increasing concentrations of disinfection by-products such as trihalomethanes when chlorine reacts with organic matter;
• contamination and biodegradation from living organisms such as insects, rodents, reptiles, birds, etc. that crawl or fall into the water;
• internal contaminants added to the water from an improper, dirty or corroding cistern/tank;
• algal growth may form toxins from cyanobacteria, and will also cause problems with taste, odour, clogging of water treatment equipment, and increased organic content, and generally impair water quality and safety;
• microbial contamination and growth of microorganisms causing biofouling of the water tank and pipe walls;
• contamination from air borne particulate or living organisms or their waste products;

Maintaining water quality during storage requires several key steps:

• Cisterns and storage tanks must be properly sized, strategically located and well-constructed.
• On a regular frequency, cisterns and tanks must be visually inspected, properly operated and maintained, and periodically cleaned and disinfected.

PIPING

If you buy or rent for long term an house it will be important to verify the piping condition and the integrity of the system.

Most of the piping in PVC U and sometime is installed underground without any protection.

From broken pipe foreign material can enter in the house hold system.

A non detected leakage can cause also severe damage to the building

Here below an extract from WHO document regarding water sanification

PVC pipe

Contaminants that may leach from PVC material include di(2-ethylhexyl) phthalate used as a plasticizer, antioxidants such as phenols and aromatic amines, lead, cadmium and organotin compounds used as heat stabilizers, acrylic processing aids, and residual vinyl chloride monomer (VCM).

Based on cancer risk assessment, a GV of 5μg/litre has been recommended for VCM by WHO, corresponding to an excess cancer risk of 10-5.

Low concentrations of VCM have been detected in drinking-water as a result of leaching from PVC pipes used in water distribution systems. A number of product standards exist which specify a quality of PVC pipes that limits the quantity of free VCM present. For example, NSFInternational requires that the residual vinyl chloride monomer content of PVC material as determined in the wall of the finished product should be less than or equal to 3.2 mg/kg (2).

The European Union has set a maximum VCM level of 1 mg/kg in materials made of PVC which are intended to come into contact with food (or drinking-water). It is further specified that VCM should not be detected in food (or drinking-water) at the limit of detection of 0.01 mg/kg (7). In order to enforce these standards, the European Union has specified the methods of analysis of VCM in PVC material (8), and in food or water (9).

The use of PVC pipes has been reviewed by a WHO Consultant Group, with special emphasis on leaching of heavy metal stabilizers and associated impurities from the pipe wall. Additives such as lead, organotin and cadmium may be used in PVC pipe production. Other potentially hazardous compounds such as mercury may occur as impurities in PVC pipe.