Water Test Results ^{note 1}

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Test results from the new filter May / June / October 2008:


This is the first test in May. The filter has not fully developed the biological layer.


This is the second test received on June 3, 2008. The new filter is now working.



This is the most recent test on the new filter




This is the first test on the new filter design with AWWA / NSF approved sand

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Below are the test results from the original filter:

Water Sample test results post-filter August 8 2007. BEFORE the .15mm sand was added. Not using a first-flush diverter on the roof water source. Water sample tests pre-filter and post-filter Oct. 18 2007. AFTER the .15mm sand was added. Not using a first flush diverter on the roof water source. Water sample tests pre-filter and post-filter for Feb 2008. AFTER the .15mm sand was added. Using a first-flush diverter on the roof water source, and the recirculating pump system wherein raw water is added once a day in amounts less than 5 gallons, with as many as 3 consecutive days where no raw water is added and temperatures are at or below freezing (32 degrees F) Below are the most recent tests on the "old filter" also called filter 1. These are the tests that show how much petroleum pollution comes from this compostion roof and how much is removed. So far, what conclusions can we draw from all of the test results? Most importanly please note that only E Coli, Fecal coliform, coliform bacteria, and petroleum hydrocarbons have been shown to be removed by these filters in this situation. ANYTHING ELSE could be present in the water and the only way to determine what is present would be to do a very expensive test for all possible contaminants. Water from different areas will contain different substances. Also, only filter 1 has been sufficiently challenged by large numbers of microbes, and successfully removed them. Although there is a preponderance of research documenting capabilites of pathogen removal far beyond what has been shown here, one cannot safely make the assumption that these filters will work well beyond the parameters shown here. You have been advised. 1.The tests show all coliform bacteria are removed: E Coli, Fecal coliform, and coliform in the filter design with .15mm sand added. 2. The addition of the first flush diverter and/or the cold weather, or a combination of cold weather, more water, and the diverter have (apparently?) reduced (but not eliminated) the amount of coliform bacteria in the water taken from this roof. 3. The biological activity of the filter does not completely stop in weather at near freezing temperatures; and after several days of inactivity while frozen, the functionality of this filter, in this situation, was not adversely effected. 4. A first flush diverter will not safely remove all bacteria from water taken from this roof. 5. Near freezing temperatures will not eliminate all coliform bacteria from the water taken from this roof. 6. It is not safe to consume unfiltered/unpurified water taken from this roof even though there is a diverter in the system. 7. From a bacteriological standpoint, the water from this slow sand filter is safe to consume in summer temperatures, fall temperatures and winter temperatures in this area - providing the filter is properly operated and maintained, and not completely frozen. 8. We do not know the nature of all chemical pollution of the water from this filter. 9. With respect to chemical pollution other than petroleum hydrocarbons, more filtering/testing would be necessary to confirm that the water from this filter / supply system is safe to consume over long periods of time. 10. We regard to health, it is prudent to err on the side of caution and assume that water from a roof is not safe to drink without filtering and testing. 11.We do not know from the tests what viruses are present or not present in the post-filter water. 12.Since coliform bacteria are removed, viruses called "Phages" or "Bacteriophages" that occupy coliform may also removed; but we do not know for sure. 13.Since the test for pathogens did not specifically include tests for all viruses; if the water is to be used on a regular basis for drinking, the use of a uv filter is highly recommended. 14.Coarse sand is not as effective as fine sand in the removal of bacteria. 15.Some of the pre-filter samples do not contain large enough amounts of coliform bacteria to aggressively challenge filter 2 and filter 3. 16.A slow sand filter will remove petroleum hydrocarbon pollutants from roof water runoff taken from the roof in ths study. 17.A first flush diverter will also remove petroleum hydrocarbon pollutants from the same water. 18.This slow sand filter still works in freezing temperatures (0 deg C). 19.The system in this study will improve the quality of roof water from this roof to exceed class AA standards for coliform bacteria presence by a factor of 5. 20.The numbers of coliform in roof water from the roof in this test can vary considerably, from none present, to thousands present. 21.The slow sand filter does not accumulate and pass on to the output water, the hydrocarbons that are present in the input water that has been flowing through it daily for 2 years. 22.The level of hydrocarbons (TPH - Total Petroleum Hydrocarbons) present in the filter output water exceeds any standards now set for TPH contamination in ground water. NOTE 1: WARNING! Racoons carry parasites (Baylisascaris procyonis) often called racoon roundworms, that are usually harmless to the racoons. These roundworms each produce millions of eggs which can persist in the environment for years and can cause serious illness in people. Chlorine, alcohol or ozone will not kill them.43, 44, 45, 46 Rooftops may be contaminated by these parasites' eggs and rainwater may pick them up and deposit them in rainbarrels.Even though a functioning slow sand filter should remove these eggs, (they are larger than 50 microns) this study has not tested for the removal of these parasites' eggs.
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