Contamination and maintenance Of Rainwater tank

Rainwater tanks are tanks used to collect and store rainwater runoff, usually through pipes, off the roof.A rainwater tank is a device that collects and holds rainwater.A rainwater catchment or collection (also known as "rainwater harvesting") system can produce 2,358 liters (623 US gal) of water from 2.54 cm (1.00 in) of rainwater on a 92.9 m² (1,000 sq ft) roof.Install rainwater tanks to utilize rainwater for later use, reduce the use of mains water for economic or environmental reasons, and help achieve self-sufficiency. Stored water can be used for watering gardens, farming, flushing toilets, washing machines, washing cars, and also for drinking, especially when other water supplies are unavailable, expensive, or of poor quality, and when due care is taken that the water source is not polluted and adequately filtered.Underground rainwater tanks can also be used to retain rainwater for later release and offer several benefits.In arid climates, rain barrels are often used to store water during the rainy season for use in the dry season.

The initial cost of rainwater tanks can be high (as people think).However, many homes use small rain barrels to collect trace amounts of water for landscaping/gardening applications, not as a drinking water substitute.These small rain barrels are usually salvaged from food storage and shipping barrels, or in some cases whiskey and wine aging barrels, and are usually quite cheap.There are also many low-cost designs using locally available materials and village-level technology, suitable for developing countries where drinking water alternatives are limited.While most are properly designed to repel mosquitoes, the lack of proper filtration or closed loop systems can create breeding grounds for larvae.For tanks used for drinking water, users will be exposed to health risks if not maintained.

Contamination and maintenance 

If rainwater is used for drinking, it is usually filtered first. Filtration (such as reverse osmosis, UV germicidal, or ultrafiltration) removes pathogens.Although rainwater is pure,it can become contaminated with airborne particulate matter as it falls or is collected.Although rainwater does not contain chlorine, contamination from air pollutants on roofs can be a risk in urban or industrial areas.Many water suppliers and health authorities, such as NSW Health, do not recommend drinking rainwater when an alternative mains supply is available.However, relatively few illnesses have been reported associated with rainwater tanks, and public health studies in South Australia (the state with the highest use of rainwater in Australia) have not found a correlation.Rainwater is generally considered suitable for drinking if it smells, tastes, and looks good;however, some pathogens, chemical contaminants, and submicron suspended metals may produce neither odor nor taste, and may Invisible.

Standards in Australia can be very different from other parts of the world that typically use rainwater for drinking water.In the United States, stormwater is increasingly being used for a variety of purposes across the country.For example, in the semi-arid western state of New Mexico, many residents of the Taos and Santa Fe areas use stormwater specifically for landscaping and even for all domestic purposes (including drinking indoor water).The "smells, tastes, looks good" criteria used in the previous paragraph is not an absolute indicator of stormwater safety.In the U.S., most people who use rainwater for drinking purposes use filtration, UV disinfection, and testing to make sure their water is safe.

Certain paints and roofing materials may cause contamination.In particular, the Melbourne Water publication advises against the use of lead paint.Tar-based coatings are also not recommended as they can affect the taste of the water.Zinc can also be a source of contamination for some paints as well as for galvanized iron or zinc-aluminum roofs, especially new roofs should not collect water for drinking purposes.Roofs painted with acrylic paint may have detergents and other chemicals dissolved in runoff. Runoff from fiber cement roofs should be discarded throughout the winter due to lime leaching.Chemically treated wood and lead flashings should not be used in roof catchment areas.Likewise, rainwater should not be collected from the portion of the roof housing the wood burner flue without a high degree of filtration.Overflow pipes or discharge pipes from roof-mounted equipment such as air conditioning or hot water systems should not have their discharge pipe flow into the rainwater tank.

A "Copper Poisoning," linked copper poisoning to plastic cans.The article states that rainwater is collected and stored in plastic tanks that do nothing to alleviate the low pH.The water was then delivered to the home through copper pipes.Highly acidic rainwater releases copper, which poisons humans.It is important to note that while plastic tanks are inert containers, collected acid rain can and should be analyzed and pH adjusted before entering the household water supply.The solution is to monitor stored rainwater with swimming pool straps, which are inexpensive and available at swimming pool supply outlets.If the water is too acidic, contact state, county, or local health officials for advice, precise solutions and pH limits, and guidance on what should be used to treat stormwater for domestic drinking water.Maintenance includes checking roofs and gutters for vegetation and debris, maintaining screens around tanks, and occasional desilting (removing sediment by draining and cleaning tanks of algae and other contaminants).

Rainwater tanks that are not properly sealed (secured to the top) can become a breeding ground for mosquitoes.A few options for dealing with mosquito problems are:

1.Flush all water once a week 

2.Smother the larvae with a small amount of cooking oil (the water is still good for landscape use thereafter) 

3.Add Bacillus Bt to the water.This bacterium does not harm animals.

4.Add mosquito fish.

Another way to store rainwater without fear of mosquito contamination is to use underground cisterns.The water temperature in the underground tank is too low (12.8 °C (55.0 °F)) for the growth of mosquito larvae, and the tank is dark to prevent the growth of mosquitoes, bacteria and algae.