Top 3 Water Quality Concerns

Nov 30, 2021

The air, water, lighting, and acoustics impact a building’s overall indoor environmental quality (IEQ). Although the primary focus of Indoor Science is air, we also care a great deal about water.  As we assess buildings, we commonly perform water quality testing for three of our top concerns. This water testing is especially important when buildings are not at full occupancy due to the pandemic or general vacancies.  

1. Legionella

Many contaminants in water will have a chronic effect on people with a long latency period measured in years. When we think of deadly water-borne illnesses, we think of diseases found in developing countries like cholera and typhoid fever. But the deadly Legionella bacteria can be found in some of the most expensive buildings in the most advanced cities in the world.  

Legionella is a bacteria that prefers warm water and it poses the greatest risk when the water is stagnant and/or recirculated and then becomes airborne. The bacteria can cause a deadly pneumonia called Legionnaires’ Disease

We prefer to conduct water sampling within the context of a Water Management Plan. An assessment will help identify the high risk areas and the plan will put a solution in place to prevent Legionella from colonizing the water system. Legionella water testing is best performed when it is acting as a quality control of the water management plan. 

2. Regulated Metals

Metals can get into drinking water from industrial discharge, runoff, erosion of natural deposits, and pipes themselves. The Environmental Protection Agency oversees the National Primary Drinking Water Regulations.  There are 11 regulated metals, each with an assigned Maximum Contaminant Levels, as listed below: 

  • Antimony < 0.006 mg/L
  • Arsenic < 0.01 mg/L
  • Barium < 2 mg/L
  • Beryllium < 0.004 mg/L
  • Cadmium < 0.005 mg/L
  • Chromium (total) < 0.1 mg/L
  • Copper < 1.3 mg/L (action level)
  • Lead < 0.015 mg/L (action level)
  • Mercury (inorganic) < 0.002 mg/L
  • Selenium < 0.05 mg/L
  • Thallium < 0.002 mg/L

Of these regulated metals, we pay special attention to the three metals that are commonly associated with plumbing systems: lead, copper, and cadmium. When buildings are vacant for long periods of time, metals in the pipes can leach into the water and result in elevated concentrations. We have seen a dramatic increase in water quality concerns as people turn on water taps after a long time of disuse, only to see brown water come out. 

3. Total coliform and E. coli

The final water quality parameter we analyze during a comprehensive IEQ assessment is total coliform and E. coli. Coliform bacteria are considered to be harmless themselves, but they act as an indicator of general contamination. E. coli is a potentially harmful type of bacteria that is an indicator more specific to fecal contamination. Together these tests are helpful tools to indicate if there are issues with the disinfection methods. 

The EPA recommends sampling the cold water only and letting the water run for 5-6 minutes.  This sampling method helps identify problems with more centralized water sources.  In addition it can be helpful to take a first draw sample to evaluate the quality of the water first coming out of the spout. 

The Total Environment

Indoor air quality consultants rarely include water quality, or may consider it to be an afterthought. We need to be champions of the total indoor environment, water included. 

In some sense, my career has come full circle.  When I was studying environmental engineering in the mid-90’s, I assumed my career would be dedicated to water. Things took an interesting turn when I had a college internship in 1995 with a company focusing completely on indoor air quality. Although my primary interest through the years has been air, I have a growing interest and appreciation for water. 

If you would like to perform a holistic evaluation of your indoor environment including the air, water, lighting, acoustics, or any other parameter, please reach out so we can discuss!