Filling a Cistern or Holding Tank With Potable Water in New Jersey

Published November 2, 2026 · A Clear Alternative Water, Pennsauken NJ, since 1991

To fill a cistern or holding tank with safe water in New Jersey, start with a clean, disinfected tank, then have certified potable water delivered by a licensed hauler in a dedicated food-grade tanker. Measure your tank's capacity first so you order the right amount, and keep a small, steady chlorine level in the stored water so it stays safe between fills. The CDC recommends cleaning and disinfecting a cistern after floods, heavy rain or any sign of contamination, then refilling it with clean, safe water. A Clear Alternative delivers certified potable water to cisterns and holding tanks in all 21 New Jersey counties; call 1-888-577-8088.

Who Uses a Cistern or Holding Tank in New Jersey

• Homes with low-yield wells. Many North Jersey homes on bedrock wells use a storage tank to bank water so the household does not outrun the well.
• Homes with failed or dry wells. A temporary tank tied into the plumbing keeps a house running while a new well is drilled or a pump is replaced.
• Seasonal homes, cabins and camps. Lake communities and camps sometimes rely on stored water for part or all of the season.
• Farms and stables. Holding tanks feed troughs and wash areas when a farm well is short.
• Businesses and construction sites. Temporary tanks provide water where there is no service connection yet.

Step 1: Know How Much Your Tank Holds

Ordering the right amount starts with your tank's capacity. Above-ground poly tanks usually have the size molded or printed on them. For a rectangular concrete cistern, measure the inside length, width and water depth in feet and multiply them together, then multiply by 7.48 to get gallons. For a round tank, multiply the diameter by itself, then by the depth, then by 5.87.

Our standard tanker carries 6,200 gallons, so most residential tanks can be filled in one trip. Tell us the tank size, how full it is now, and how many people or animals it serves, and we will help you plan how often to schedule deliveries.

Step 2: Inspect and Clean the Tank

Fresh water poured into a dirty tank is no longer fresh. Before the first fill, after a long period sitting empty, or after any flood, inspect the tank:

• Check the lid, hatch and vent screens. They should close tightly and keep out insects, rodents, leaves and surface water.
• Look for cracks, especially in older concrete cisterns, where groundwater or runoff can seep in.
• Look for sediment, slime or algae on the walls and floor.
• Make sure the overflow drains away from the tank and cannot back up into it.

The CDC's fact sheet on cleaning and disinfecting cisterns describes removing all debris and water, scrubbing the inside with a stiff brush and a solution of about 1 cup of unscented household bleach in 10 gallons of water, then rinsing and draining. Never climb into a closed tank alone. Confined spaces can hold dangerous air; use ventilation, have someone with you, or hire a professional tank cleaner.

Step 3: Disinfect the Tank and Plumbing

If the tank was contaminated, or if it feeds indoor plumbing and has been out of service, the CDC recommends a shock disinfection:

1. Close the valves to any filters or other equipment connected to the tank, and clean those according to the manufacturer.
2. Add about 3 cups of unscented liquid household bleach for every 100 gallons of water in the tank.
3. Open each faucet and run it until you smell chlorine, then turn it off.
4. Leave the solution in the tank and pipes for at least 12 hours. Do not drink, cook or bathe with this water.
5. Drain all of the water, following any local rules about where heavily chlorinated water may go.
6. Refill with safe water, then run each faucet until you no longer smell chlorine.

Many homeowners have a well contractor or plumber handle this, especially when the tank is tied into a pressure system.

Step 4: Fill With Certified Potable Water

Where your water comes from matters as much as the tank. A hose from a neighbor, a pond or a truck that also hauls non-drinking water can undo all the cleaning you just did. Look for:

• A licensed potable water hauler. Ask for the hauler's license number. A Clear Alternative operates under New Jersey potable water hauler license #0704582.
• A dedicated potable tanker. The tank, hoses and fittings should be used only for drinking water.
• Clean hose handling. Hose ends should be capped when not in use and never dragged through mud or laid in standing water.
• An approved source. The water should come from a public supply that is treated and tested.

Step 5: Keep Stored Water Safe Between Fills

Water that sits in a tank slowly loses its chlorine, especially in warm weather. To keep it safe:

• Maintain a small chlorine level. After refilling, the CDC suggests adding about 1 tablespoon of unscented household bleach for every 100 gallons to help prevent germs from growing. A simple chlorine test kit can check free chlorine.
• Keep it cool and dark. Shade above-ground tanks and use opaque tanks to limit algae.
• Use it and refill it. Water that turns over regularly stays fresher than water sitting for months.
• Test it. If the tank serves a home, test for bacteria periodically and after any problem, such as flooding or a damaged lid.
• Clean on a schedule. Inspect at least once a year and clean when sediment builds up.

How Often to Schedule Deliveries

The right schedule depends on how much water you use and how big your tank is. The simplest way to find out is to note the level right after a fill, check it again a week later, and work out how many gallons you used. For example, a household that uses 300 gallons a day goes through about 2,100 gallons a week, so a 2,500-gallon tank would need a delivery roughly every week, while a 6,000-gallon tank could go nearly three weeks. Farms, camps and businesses vary much more with the season.

Once you know your number, we can set up a standing delivery so you are not watching the gauge. Build in a cushion so a storm, a holiday or a busy week does not leave the tank empty. Most customers reorder when the tank drops to about a third full.

Signs Your Tank Needs Attention

• The water has a musty smell, a slimy feel or visible particles.
• The chlorine level drops to zero soon after each fill.
• The level falls faster than your usage explains, which can mean a leak.
• Insects, leaves or droppings show up near the hatch or vent.

Any of these is a reason to inspect, clean and disinfect before the next fill.

Cistern Problems in Winter

Above-ground tanks and exposed lines can freeze in a New Jersey winter. Insulate or heat-trace exposed pipes, keep tanks in a protected spot if possible, and avoid letting a buried cistern run so low that the intake pulls sediment. If a frozen or damaged system leaves you without water, our emergency water delivery team works around the clock.

Cistern and Tank Delivery Across New Jersey

We deliver to homes, farms, camps and businesses from Sussex and Warren down to Cape May. Our guide to potable water delivery in Sussex County covers dry wells and cisterns in North Jersey. Farms using a holding tank for animals can read our guide to water for livestock during a drought, and contractors can see our construction water page. Check our service areas to confirm your town.

When to Call A Clear Alternative

Call us when a cistern needs its first fill, when a well can no longer keep up, after you have cleaned a tank following a flood, or when you want a regular delivery schedule. A Clear Alternative is a family-run company that has served New Jersey since 1991 from 9230 Collins Ave in Pennsauken. Call 1-888-577-8088 or request a quote online with your tank size, location and how the truck reaches the tank.

Frequently Asked Questions

Can you fill a cistern with drinking water in New Jersey?

Yes. A Clear Alternative delivers certified potable water to cisterns and holding tanks in all 21 New Jersey counties under potable water hauler license #0704582.

How do I disinfect a cistern before filling it?

The CDC recommends adding about 3 cups of unscented household bleach per 100 gallons, running each faucet until you smell chlorine, letting it sit at least 12 hours, then draining and refilling with safe water.

How many gallons does one delivery hold?

Our standard tanker carries 6,200 gallons, which fills most residential cisterns and holding tanks in one trip.

How do I keep water in a holding tank safe?

Keep a small chlorine level, shade the tank, keep lids and vents sealed, use and refill the water regularly, and test for bacteria periodically.

How do I calculate how much water my cistern holds?

For a rectangular tank, multiply length, width and water depth in feet, then multiply by 7.48. For a round tank, multiply diameter by diameter by depth, then by 5.87.

Is it safe to climb into a cistern to clean it?

Not alone. Closed tanks are confined spaces that can hold dangerous air. Ventilate the tank, have someone with you, or hire a professional tank cleaner.