Is Aluminum Pipe Safe for Drinking Water?

When designing or upgrading water supply systems, material choice is critical to ensure safety, longevity, and compliance with health standards. Among various piping materials, aluminum pipe is often considered for its light weight, corrosion resistance, and cost-effectiveness. This raises an important question for engineers, builders, and homeowners: Is aluminum pipe safe for drinking water?

In this comprehensive article from sasaaluminum, we explore the safety, advantages, concerns, and best practices related to using aluminum pipe in potable water systems.

Properties of Aluminum Pipe Relevant to Drinking Water

Aluminum pipe is known for:

• Corrosion resistance due to its natural oxide layer

• Light weight for easy handling and installation

• Durability in many industrial and structural applications

• Non-magnetic and non-sparking characteristics

• Recyclability, supporting sustainable infrastructure

These properties make aluminum pipe popular in industries such as construction, automotive, and marine, but how do they translate to potable water use?

Can Aluminum Be Used for Drinking Water Systems?

Aluminum pipe can technically carry drinking water, but its safety and suitability depend on several factors:

1. Health Standards and Guidelines

Regulatory agencies like the World Health Organization (WHO) and national health authorities have established limits on aluminum levels in drinking water. The WHO recommends that aluminum concentrations in drinking water should not exceed 0.2 mg/L.

Aluminum piping systems must be designed and maintained to prevent the release of aluminum into the water beyond these safe limits.

2. Corrosion and Leaching

Aluminum is resistant to general corrosion, but under certain conditions, such as:

• Acidic or low pH water (below pH 6.5)

• High chloride or sulfate content

the protective oxide layer can break down, increasing the risk of aluminum leaching into the water supply.

3. Compatibility with Drinking Water Treatments

Some water treatments, such as chlorination, can alter water chemistry and affect the corrosion resistance of aluminum pipes. Additionally, aluminum salts are sometimes used as coagulants in water treatment, so careful monitoring of total aluminum levels is necessary.

Advantages of Aluminum Pipe for Water Systems

While aluminum pipe is not commonly used for drinking water delivery compared to copper, stainless steel, or plastic, it does offer some benefits:

• Light weight makes it easy to install, especially in multi-story buildings or remote areas

• Corrosion resistance in neutral pH and clean water systems

• Cost-effective compared to some stainless steel and copper options

• Eco-friendly, with aluminum being fully recyclable at end of life

sasaaluminum supplies aluminum pipes designed for various applications, and can advise on suitability for water systems.

Concerns About Using Aluminum Pipe for Drinking Water

1. Potential for Leaching

In certain water chemistries, aluminum may slowly dissolve into the water supply, potentially leading to levels above recommended health limits.

2. Pitting Corrosion in Aggressive Waters

If the water has low pH, high salinity, or fluctuating chemical balance, localized pitting corrosion could occur over time.

3. Regulatory Approval

In many regions, building codes and drinking water regulations specify approved materials for potable water systems. These often prioritize:

• Copper

• Stainless steel

• PEX or CPVC plastic

Aluminum pipe may not always meet local code requirements for potable water systems without additional approvals or protective measures.

Best Practices for Safe Use of Aluminum Pipe in Water Applications

If aluminum pipe is considered for a water system:

• Test the water chemistry to ensure it is compatible with aluminum’s corrosion resistance properties

• Apply protective coatings or liners inside the pipe to prevent direct contact with water

• Monitor water pH and adjust if necessary to maintain a neutral to slightly alkaline environment

• Use dielectric fittings to avoid galvanic corrosion when aluminum connects to other metals

Alternative Uses of Aluminum Pipe in Water Systems

While aluminum pipe may not be ideal for primary drinking water supply lines, it is successfully used in:

• Non-potable water systems such as irrigation, industrial cooling, or greywater reuse

• Rainwater harvesting systems

• Structural supports for water system installations

• Compressed air or utility fluid delivery

Comparing Aluminum Pipe to Other Drinking Water Pipe Materials