There are more than 7.5 billion people in the world as of 2020.  Fifty years ago, the population was roughly half of that.  Though the population growth rate has slowed from the rapid pace set in the 20th Century, the number of people still is expected to rise.  More people means more resources consumed. All people need water to survive, but it’s a finite resource – there is only so much of it readily available on Earth.

Less than 1 percent of water is available for human use, according to the Environmental Protection Agency.  Most of the Earth – about 71 percent – is covered in water, with the oceans holding 96.5 percent of that amount.  Through the hydrologic cycle, water always returns to Earth.  However, it’s never in the same place, quantity, or quality.  What was once drinking water might return to Earth as vapor.

Since water is such a precious resource, is it little wonder humans have devised ways to store water for when it’s needed. Potable, fire protection, industrial, and agriculture are four reasons water is typically stored.

Potable water

The United Nations recognizes access to clean drinking water as a human right.  Sadly, 1 in every 3 people does not have access to clean water, according to the World Health Organization.

One would think that water would be readily available on a planet that’s 71 percent water.  However, only 2.5 percent is freshwater.  The rest is saltwater, which isn’t suitable to drink unless it goes through the expensive and time-consuming process of desalination.  Of that 2.5 percent, only about one percent is readily available since the rest is in glaciers and snowfields.

Available freshwater is for potable, agricultural, and industrial needs.  Potable water is for drinking. It’s generally drawn from lakes and freshwater streams, treated and stored in ground tanks or elevated water tanks until it’s circulated into pipes that feed into buildings.

Individuals can store water in small tanks, but municipalities have water systems with large capacity water storage tanks.  Water can be stored in underground and aboveground storage tanks, which can be steel, concrete, wood, or fiberglass.

Storing treated water in ground and elevated storage tanks help keep out harmful contaminants found in rivers, streams, and springs.  Animal feces, mercury, and other chemicals can contaminate freshwater sources.  Municipal water must meet strict state and federal rules and regulations, so it has a relatively low safety risk.  It should be chemically treated before it’s considered ready to drink.

Potable water tanks and elevated water storage tanks should be inspected and washed out “at least once every 3 years, and where water supplies have sediment problems, annual washouts are recommended,” according to American Water Works Association Manual 42. Both inspections and cleanouts on storage tanks can be performed dry, with divers, or with remotely operated underwater vehicles.

Well water is also used as drinking water.  It’s not chlorinated or treated, so there are risks involved in drinking well water.  Much like other water infrastructure, if wells are built in a good location and well maintained, they are less susceptible to contamination.  Wells located near animal agriculture sites, septic tanks, or flood zones have a greater risk of contamination.

Fire protection

Fire protection has evolved over the years.  American settlers would beat back the flames with wet burlap sacks or formed a human chain to pass buckets full of water they splashed on the fire.  Modern firefighters have fully equipped firetrucks with hoses that can connect to high-pressure hydrants.  Many buildings have sprinkler systems with pipes that feed into fire protection tanks.

Fire protection tanks have a fire pump connected to pipes.  Once the fire pump is activated, water travels from the tank to the sprinkler system.

NFPA 25 states that storage tanks without cathodic protection should be inspected and cleaned out every three years, while tanks with cathodic protection should be cleaned every five years.  Maintenance and cleanouts help keep the water clean from sediment and other contaminants.  Clean water, clear of sediment and dirt clumps, won’t clog up the pipes.  Heaters and insulation can guard against the tank freezing.  A frozen fire protection tank is a useless tank.

Divers and ROVs can both inspect or clean out a tank without draining it.  As the name implies, dry cleanouts require a tank to be drained before it can be inspected or cleaned out.


As the world’s population continues to expand, more food is necessary to sustain life.  That means more water is needed, not only for drinking purposes but to irrigate crops.

Agriculture accounts for about 69 percent of all Earth’s freshwater use, according to  That’s compared to 12 percent for households and municipal, and 19 percent for the industrial sector.  Crop failure would be more widespread if rainfall were the only way to water crops.  Farmers have longstanding water harvesting techniques to counter dry spells when there is little or no rain.  Irrigation waters crops that rely on channels and machinery.  Irrigation helps protect during dry periods and supplements rainfall during wetter periods.


Fabrication, processing, cooling, washing, transporting – all these industrial processes require a lot of water.  Large quantities of water are used to make food, paper, and chemicals.  Affluent first-world countries allot about 59 percent of their water for industrial needs, according to the Commission for Environmental Cooperation.  Impoverished third-world countries where there’s less water infrastructure designate about 8 percent of their water supply for industrial use.

Companies rely heavily on API – or American Petroleum Industry – style storage tanks for their industrial needs. We are tank builders that can construct API style tanks that are anywhere between 35,000 to 10 million gallons of capacity.  Pittsburg Tank & Tower Group builds API-620 and API-650.  The former stores low-temperature liquids at high pressure, while the latter stores high-temperature liquids at low pressure.


The tanks can serve many industries, including petroleum, chemical, paper, terminals, potable water, fire water, power, wastewater, and dry bulk. Specialty services include cryogenic, thermal energy, double containment, and elevated temperature.