Putting a liner in your cistern, whether you install it during initial construction or years later, will make maintenance easier for the lifespan of the structure. Much like lined ponds, lined cisterns are easily cleaned and disinfected as needed with much less work. Even if you don’t need to clean your cistern regularly, because it’s only used for non-potable water, you’ll find other maintenance tasks easier with the liner in place. Discover how flexible geomembrane liners in particular protect cisterns from damage and reduce the work necessary to keep them stable as the years go by.
Preventing Algae Adherence
Algae growth is a major problem in some cisterns, especially those built from water tanks or ponds located at the surface or above ground. Warmth and sun exposure encourages algae growth even in enclosed tanks. Algae reproduce rapidly, clogs up filters and pipes, and can release compounds that make water unpleasant or unsafe to drink. The roots of the tiny plants also break down the interior surface of the cistern, especially if the material is concrete or plastic. An impermeable and smooth liner reduces algae’s ability to cling tightly to the sides of the cistern. Cleaning out the green sludge is easy, and you can scrub the liner to remove residues without worrying about disturbing a damaged concrete surface.
Controlling Corrosion and Erosion
Chemical resistant liners also extend the lifespan of the tank and reduce maintenance by preventing corrosion. Even fresh water, designated for drinking, can still cause corrosion issues inside of concrete and steel cisterns because of the reactivity of chemicals used for water purification. Chlorine may be perfectly safe to drink in small amounts, but it’s very destructive to many cistern materials. A cistern may need a complete liner to prevent corrosion since gases and evaporating water can carry the compounds to the ceiling of the tank or vault. Erosion is another problem over long periods of time. Large cisterns often have enough air movement to cause water to lap gently against the sides. That gentle wave action slowly wears away the material. A sacrificial liner prevents that erosion action and is far easier to replace.
Blocking UV Damage
For open air cisterns, that are exposed at the surface, adding a geomembrane liner is the best way to protect the sides and walls of the structure from UV degradation. Almost all materials break down more rapidly when exposed to constant sunlight, including concrete and fiberglass. A UV resistant liner, made from RPE, blocks the light from reaching any part of the cistern including the exterior if you completely cover the surface. UV light is great at penetrating water, so a full cistern still degrades on the bottom and sides unless it’s lined.
Covering Cracks in Materials or Sealants
Flexible liners, in particular, are great for creating a smooth surface that is hard to find in older cisterns. As the material holding the water slowly breaks down, steel and concrete go from relatively smooth to pitted and rough. Tiny cracks, that don’t allow water to leak out, still make it tricky to completely clean and sanitize a cistern. Adding a flexible geomembrane liner creates a smooth, crack-free surface that is easy to inspect and clean. With a reduced amount of water pressure continuing to press against the crack, it’s less likely to grow over time.
Reinforcing Access Areas
The areas around cistern hatches and openings tend to see a lot of traffic, especially when monthly or quarterly maintenance is required. If you let these openings become muddy and disturbed, dirt and debris is easily tracked into the cistern or knocked loose when opening the hatch. Smoothing a layer of liner over the surfaces around access areas is the best way to prepare them for regular use. You may also want to consider gravel and French drains that direct water away from cistern access areas, so they stay dry and sanitary for maintenance visits.
Ensuring Complete Disinfection
Drinking water cisterns especially need regular draining, sediment removal, and disinfection, to remain safe enough for daily use. Even if a cistern is just part of a storage system for water that is later sanitized or filtered, it should be occasionally cleaned to continue holding the same volume as sediment accumulates. A solid, noticeable liner layer made from geomembrane allows for more thorough, faster cleaning and disinfection. It’s clear when the sediment has been completely removed because the contrast color of the liner is easier to see than aged concrete or steel. With fewer nooks and crannies found across the various surfaces of the lined cistern, there’s less of a chance of bacteria lingering and spreading through the water supply.
Most cisterns only need routine inspections for leaks and occasional cleaning once they’re lined. Spending a little time and money on a major internal improvement can make the difference between a productive cistern and a troublesome one. Don’t let cistern maintenance convince you that it’s better just to drain it and fill it in. No matter what cistern maintenance struggles you are dealing with, there’s a good chance that a liner from BTL Liners is the solution you need to reduce your workload.