Dispelling Common Water Quality Perceptions

For over two decades, my observations regarding residential water quality have revealed a consistent pattern of common misconceptions. Homeowners often hold strong, yet sometimes unfounded, beliefs about the safety and purity of their water, whether it originates from lakes, drilled wells, shore wells, cisterns, or rivers. These perceptions, often passed down through generations or based on anecdotal evidence, can lead to a false sense of security regarding drinking water safety.

A widespread belief is that water from a private source is inherently safe, particularly if it's been deemed acceptable in the past or if the surrounding environment appears undisturbed. For example, some assume their well water is pristine simply because previous generations never experienced issues, or that lake water remains safe due to a lack of recent development. 

Another frequent assertion, particularly concerning shore wells, is that they are "lake water fed directly from the lake," implying natural filtration. 

Similarly, new homeowners with drilled wells often believe that an initial "good" test result, coupled with the well's depth, guarantees it's free of bacterial contamination. These diverse perceptions share a common thread: the conviction that the water is safe without further assessment or treatment. 

rather than a conclusion based on comprehensive understanding.

One of the most prevalent misconceptions revolves around septic systems and their potential impact on well water. Many homeowners believe that a significant distance between their septic system (typically at the back of the house) and their well (often in the front) automatically prevents contamination. This perception is common in rural subdivisions lacking municipal water and sewer services, where each home relies on its own well and septic system. 

However, the reality is that all septic effluent is discharged into the ground through weeping tile. The subsequent movement of this effluent is highly dependent on local geological factors, including soil layers, rock formations, and the depth and flow of the groundwater table. Contaminants from a septic system can travel considerable distances underground, potentially impacting nearby wells, regardless of their perceived separation. Understanding groundwater flow patterns is crucial for assessing this risk.

The Limitations of Public Health Unit Testing

Many homeowners rely solely on a single water test conducted by the local Public Health Unit, often at the time of purchase or sale of a property. The perception is that this test provides a comprehensive assessment of overall water quality and that the Health Unit would flag any significant issues. 

It's important to clarify that Public Health Unit tests typically focus on microbiological contaminants, specifically total coliform and E. coli. While these are vital indicators of potential fecal contamination, they do not screen for a wide array of other possible contaminants, such as:

• Heavy Metals: Arsenic, lead, mercury, etc.
• Chemicals: Pesticides, herbicides, industrial solvents, etc.
• Pharmaceuticals and Personal Care Products (PPCPs): Traces of medications, cleaning products, etc.
• Naturally Occurring Substances: Radon, uranium, fluoride (at elevated levels).

Understanding UV Disinfection Systems

Ultraviolet (UV) disinfection systems, often referred to as "blue lights," are widely marketed and perceived as a complete drinking water purification solution. They are frequently a benchmark requirement in real estate transactions, with the general perception being that "my water is safe if I have a UV installed," especially if the "green light" indicator is on.

However, a UV system provides only disinfection by deactivating bacteria, viruses, and some protozoa. It does not physically remove any contaminants from the water, such as sediment, chemicals, or heavy metals. For effective operation, UV systems have minimum incoming water quality requirements, including clarity (low turbidity) and hardness levels, which are often overlooked.

The UV lamp/bulb is protected by a quartz sleeve that can accumulate scale and fouling, reducing the UV light's penetration and disinfection capability. 

Regular cleaning of this sleeve and timely lamp replacement are essential, yet often neglected. Without adequate pre-filtration for sediment and other physical contaminants, the UV system's effectiveness can be severely compromised.

The Truth About Drilled Wells and Bacteria

A common belief is that deep water sources, particularly drilled wells extending 100 feet or more into the ground, cannot harbor bacteria because they are too deep for microbial survival. This perception often leads well owners to forgo regular testing. However, geological formations, especially in areas with heavy rock, can contain a network of deep fissures and fractures. 

These natural pathways can allow surface water, and the bacteria it carries, to infiltrate deep into the ground and reach the water table. Observations have shown the presence of bacteria in wells as deep as 200 feet, highlighting that depth alone does not guarantee bacterial purity.

Brita filters and many refrigerator water filters, while popular, are not designed to be "remove-all" treatment systems and often carry warnings against use with microbiologically unsafe water. Their primary function is typically to improve taste and odor by removing chlorine using activated carbon media.

Despite these limitations, these filters are widely used on rural unchlorinated wells and lake water by homeowners who believe they will make the water safe for drinking, regardless of the incoming water quality. This is a significant misconception. Furthermore, activated carbon media, under certain conditions, can become a breeding ground for bacteria, potentially worsening water quality if not regularly replaced.

A Holistic Approach to Water Safety

Ultimately, a comprehensive understanding of water quality requires moving beyond superficial perceptions and embracing a complete picture of overall safety. Water quality should not be viewed as a "snapshot" in time for one or two contaminants, but rather as an ongoing assessment. 

Water treatment equipment should be selected and installed based on thorough water testing and a clear understanding of its intended purpose and limitations. Furthermore, careful consideration should be given to the surrounding environment of the water source, as activities on the surface can significantly impact lake and groundwater quality. 

The deeply ingrained belief that water is safe in its "original state" without any treatment is a perception that urgently needs to be challenged through education. By promoting accurate information and encouraging proactive measures, we can significantly enhance water safety for everyone.

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