Q: We have 20 years experience in the water treatment industry. We have never seen chemistry like this, nor have our suppliers. What advice can you give on this problem? (Editor’s note: The submitter provided a complete laboratory analysis, which our Tech Reviewers .)
A: The water analysis looks typical of contamination from acid mine drainage (AMD), which is characterized by very low pH (2.8), high iron (200 mg/L) and high sulfate (1,200 mg/L). I don’t see any result for sufide (H2S). Was it determined or did the water have a very distinctive rotten egg smell? The high arsenic (1.9 mg/L – 1,900 ppb) is characteristic in certain mountainous areas and areas having geothermal activity in New Mexico. An internet search on acid mine drainage will provide explanations on what causes the low pH, high iron and other extreme contamination issues, as well as treatment options.
If this was an attempt to find an acceptable well water, it appears that communicating with a local university geologist might be beneficial for determining if another drilling location could be found or an attempt at drilling at a different depth would provide any better results.
Gary Hatch, Ph.D.
Director, R&D, Pentair Filtration, Inc.
A: I agree with Gary. They should seek another water source. This water would be very expensive to treat and would be very toxic if the treatment failed. It would need back up to the back up. If this is their only water source, we could suggest a treatment (but it will take a small chemical plant to do so).
C. F. ‘Chubb’ Michaud, C.E., CWS-VI
Q: I am in Honduras, Central America. I need information on water treatment options for iron. I have a film of red color on the surface of a water well with and the sanitary tank has turned red because of the water. We chlorinate the well but iron problems continue. We also add bensalconium chloride (Alkyl Dimethyl Benzil Ammonium Chloride) in solution and us an aeration pump. I want to try to find a greensand type of filter or an ozone filter that will resolve this problem. Please let me know what is the best option.
Grupo Industrial DEQUIN
A: I can only recommend continuous chlorination/filtration.
Peter Cartwright, P.E., CWS-VI
Cartwright Consulting Co.
A: If this is indeed iron bacteria, continuous oxidation with post-filtration is the most logical choice and will help with ferrous iron also. The water should be tested for the following before attempting to specify treatment methodologies: hardness, iron, TDS, pH, total alkalinity, chlorine demand, ORP (at the very least).
Intermountain Soft Water, Inc.
(Editor’s note: air-cleaning products are becoming a value-added product for water treatment dealers. Questions about these systems will occasionally be included in this column.)
Q: What are the pros and cons of portable and furnace-mounted air cleaning products and why would one company want to choose one product to sell over another?
A: Many versions of both are on the market, though portable units are the most widely available. In most cases, portable units only can treat the air that gets to the machine. Some high quality portable systems can deliver the appropriate balance of airflow and efficiency; however, they will only be capable of filtering the air that is recycled around to it. Portables can act as a partial or whole home solution if you are delivering enough air where it is ventilating clean air throughout the ductwork of the rest of the home.
Furnace mounted systems usually incorporate lower efficiency filters due to pressure drop of the filter; standard heating and cooling system will not tolerate a high efficiency filter. Standard furnace systems will only treat the air when the fan is running; the only way to effectively treat air is through 24/7 operation.Ultraviolet (UV) systems have become popular, but to be truly effective in the ductwork, measurement of bulb intensity and the airflow velocity by the bulb for proper decontamination of Bio-Aerosols is crucial. In most cases this is too expensive to be done residentially. Bypass HEPA systems (recent market arrivals) only treat about 10 percent of the air the furnace is pushing through. Bypassing the main system with 200 CFM of clean air, when the standard heating and ventilation system is meant to treat 2,000 CFM, results in a mere 10 percent being cleaned. Some companies provide installation, though that can add 15-20 percent to the cost of the product, while increasing the company’s liability.
Vinny Lobdell, Jr.
HealthWay Home Products Inc.