Some of the Results from the water testing done on catchment water in Volcano
- with some Graphs for Volcano and HOVE -

from the e-mail of July 21, 2009

University of Hawai'i at Manoa
College of Tropical Agriculture and Human Resources
Department of Natural Resources and Environmental Management

July 21, 2009

Dear Participants in the Volcano Water Testing;

We promised you test results for Sulfate and we finally have some data for you. Sorry it took so long. We also were able to fund testing for Fluoride and Chloride and have those results for you too. We knew the concentrations of these particulates were low in rainwater but we wanted to make sure that they didn't accumulate to high levels in your tank water. We found out that they did not accumulate to especially high levels. In a nutshell we did not find sulfate, fluoride or chloride levels high enough to be a concern in any of the tested catchment waters. All were well below EPA standards. Fluoride has an EPA maximum allowable amount called MCL. There is fluoride in the volcanic plume but it did not accumulate to concentrations that are of concern.. Sulfate and Chloride have secondary EPA standards meaning that they are mostly a cosmetic concern. They can also be indicators of volcanic particulates but chlorine treatment of your water can also raise Chloride levels. We can summarize what we found as follows

Contaminant MCL or Standard Volcano Values Median Value Results
Sulfate 250 ppm 0.00 – 13.20 ppm* 2.14  ppm Below level of concern
Chloride 250 ppm 0.23 – 18.91 ppm** 2.32  ppm Below level of concern
Fluoride 4 ppm 0.00 – 0.33 ppm* 0.047  ppm Below level of concern

*One sample was way above the range of other samples but still well below EPA standards. We did not include it so as not to skew the graphs. We are retesting that sample.

**Chloride range is large but in actuality only 4 samples went above 9.0, most were much lower.

After doing the pH testing in Ocean View and Volcano it is very clear that using baking soda or similar treatments to raise the pH is very effective and it is recommended. Besides metal leaching we suspect that the acidic water may be eroding tooth enamel but have no research to back up this theory. 

Some of the catchment samples indicate that more baking soda (or similar treatment) is being added than is really needed making the pH higher than is recommended. Although there are no known health concerns with the higher pH, it may affect the taste and the physical properties (may feel "oily" or "soapy") and so we recommend that you try and keep it around 7.0 if possible. A pH of 6.5 – 8.0 is good.

We have included some comparative information between your subdivision and Ocean View Estates soon and before the end of the year we hope to have done similar studies in lower Puna to compare with your results. We'll let you know how those come out too.

If you prefer not to get more notices from us, just let us know and we'll remove you from our list. If you got this note by letter and you have e-mail, would you send us your e-mail address so we can save some time and postage costs? It would be a big help to us. Thanks.

If you would like to ask me questions about using baking soda or other treatment options, just drop me an e-mail or give my office a call: 981-5199.



Trisha Macomber, MPH  ---- Cooperative Extension Service

Dr. Don Thomas ---- Center for the Study of Active Volcanoes

Graphs of Sulfate, Fluoride, Chloride and pH in Catchment waters in Volcano and HOVE