Protect Your Water Tank from Groundwater Contamination and Tree Root Intrusion

Water tanks play a vital role in many water supply systems, providing a safe and reliable water source for households, farms, and businesses. But they can be vulnerable to contamination from groundwater and tree roots. Our on-the-ground tank expert, discusses the risks of groundwater contamination and root intrusion and shares his practical tips for preventing these issues.

The Risks of Groundwater Contamination

Groundwater Contamination in a Rural Tank

Groundwater contamination can occur when water from the surrounding soil or aquifer enters the tank through cracks, holes, or poorly sealed connections. This contamination can result from several avoidable issues:

• Poor installation or maintenance

  Improper installation or a “set-and-forget” approach to maintenance can leave your tank vulnerable from day one. Tanks require a solid foundation and regular maintenance to remain in good condition.

  • Installed on an uneven or unstable surface – This can lead to stress fractures or uneven pressure on the tank over time.

  • Inadequate foundation or drainage – Poor drainage allows water to pool around the tank base, increasing the risk of structural damage and contamination.

  • Lack of regular cleaning and inspections – Without scheduled maintenance, sediment buildup and small faults can go unnoticed.

  • Small issues can worsen over time – what starts as a minor leak or crack can develop into a major contamination issue if left unchecked.

• Cracks or Holes in the tank

  Even the most durable tanks aren’t immune to wear and tear. Over time, a combination of environmental stress and age can create structural weaknesses that allow groundwater to seep in.

  • UV exposure and temperature fluctuations – Prolonged sun exposure and seasonal temperature shifts can cause materials (especially plastic) to become brittle and prone to cracking.

  • Ground movement or unstable foundations – Erosion, or poorly prepared ground, can cause tanks to shift or settle unevenly, creating stress fractures.

  • Overtightened fittings – Applying too much force to fittings or attachments can create pressure points that lead to splitting or hairline cracks.

  • General material fatigue – Tanks naturally degrade over time, especially without proper care, making them more susceptible to leaks and breaches.

• Loose or Poorly Sealed Connections

  The connection points between your tank and pipes are often the first places to fail. If they're not properly sealed or maintained, groundwater contamination can sneak in unnoticed.

  • Improperly installed inlet or outlet pipes – Misaligned or poorly fitted pipes leave gaps where water can enter or escape.

  • Worn-out seals or gaskets – Rubber seals degrade over time, especially when exposed to sunlight or fluctuating temperatures.

  • Shifting pipes due to soil movement or water pressure – Movement in the ground or high-pressure flows can loosen fittings, causing leaks.

  • Small leaks developing over time – Minor drips at join points may not seem urgent, but can gradually turn into serious contamination risks.

• Lids Sitting at or Below Ground Level

  The tank lid is a crucial barrier, but only if it’s elevated above potential runoff. When lids sit flush with or below the soil line, they create a prime entry point for contamination.

  • Rainwater and surface runoff pooling around the lid – Water collecting around the lid can seep into the tank, bringing contaminants with it.

  • Dirt, bacteria, and debris entering through the lid – this can be especially apparent during storms. The splashback, or pooling of water, can carry unwanted material straight into the tank.

  • No riser tube to lift the lid – A riser tube elevates the access point, helping prevent runoff and debris from getting inside.

  • Increased risk of pests – Lids at ground level are more accessible to insects, frogs, rodents, and other unwanted visitors.

The Risks of Tree Root Intrusion

Tree roots that have pushed in through a cracked pipe joint - looks like something out of a horror movie!

While groundwater contamination often enters through weak points, tree roots can physically force their way in, causing structural damage and long-term issues with both tanks and pipes.

Tree roots naturally seek out water and nutrients, and they’re incredibly persistent. As a tree matures, its root system can stretch far beyond the canopy, sometimes two to three times the width of the tree itself. If a water tank or underground piping lies in the path, the roots won’t hesitate to grow toward it, especially if they detect moisture.

Common risks from tree root intrusion include:

• Damaged pipes

  Roots are surprisingly strong and can infiltrate even the smallest cracks or joints in your pipes. Once inside, they expand and grow, causing:

  • Blockages that restrict water flow or cause backflow

  • Cracks or splits in PVC or older concrete piping

  • Complete pipe collapse in extreme cases

• Tank damage 

  If roots grow underneath or alongside your tank, they can exert pressure on the base and walls. Over time, this pressure may cause:

  • Hairline cracks or splits in the tank surface

  • Structural stress at connection points

  • Roots physically breaking through the tank walls in search of water.

• Unseen issues beneath the surface 

  Because root intrusion happens underground, it often goes unnoticed until the damage becomes severe. Signs such as unexplained leaks, reduced water pressure, or unusual water quality can all indicate root-related problems.

• Recurring contamination and repairs

  Once roots breach the system, they leave a pathway for sediment, bacteria, and groundwater to enter. Even if you remove the roots, the damage they leave behind can continue to cause problems unless properly repaired and reinforced.

Why Regular Maintenance Matters

Routine tank maintenance is crucial for preventing groundwater and tree roots from entering your tank. At Cross Country Water Tank Cleaning, we help you keep your tank clean, secure, and functioning correctly. Our team inspects tanks, identifies risks early, and provides expert cleaning and maintenance to protect your water supply.

Can You Save Contaminated Water?

Yes, you often can. If sediment or groundwater has contaminated your tank, we can help recover the water through proper filtration or chemical treatment. Our team at Cross Country Water Tank Cleaning will assess the situation and recommend the right approach. We utilise filtration systems and chemical treatments to help settle sediment out of solution, removing contaminants and restoring your water to a safe and usable state.

Prevention and Mitigation Strategies

To protect your tank and pipes from both groundwater and root intrusion, consider these tips:

• Inspect regularly – Look out for cracks, signs of wear, or contamination. Or let the team at Cross Country Water Tank Cleaning do it for you.

• Install correctly – Ensure your tank has a tight-fitting lid, proper drainage around the tank, and a riser tube if needed.

• Manage nearby trees – Consider the location of trees near your water tank and pipes. If possible, plant trees at a safe distance from the tank and pipes to prevent root intrusion.

• Use root barriers – Install root barriers around your tank and pipes to prevent tree roots from growing into the tank or pipes.

• Choose strong piping – Use pipe materials and designs that are resistant to root intrusion, such as PVC or HDPE pipes.

Your water tank is one of the most important assets on your property, so it makes sense to protect it properly. Groundwater contamination and tree root intrusion are two of the most common (and preventable) causes of tank damage, but with the right knowledge and maintenance plan, you can avoid the stress and cost of unexpected repairs.

At Cross Country Water Tank Cleaning, we’ve seen firsthand how quickly small issues can escalate into bigger problems. Whether you need a one-off clean, regular inspections, or advice on tank setup and tree placement, we’re here to help.