Colorado legalizes rain water harvesting

The governor of Colorado has signed into law a bill that allows anyone to collect rainwater from their roof. It is now legal to collect rainwater in Colorado. 

HB 16-1005 is the bill that was signed May 12, 2016.  

More here:

And here:

This is a big change from the past one hundred and fifty years or so. It has been a crime in Colorado set up a rain water harvesting barrel until May 12, 2016. Now it is legal. The times, they are a changin’.

Now I am sure there will be people ranting about something they find bad about this. There will be nit-pickers that will find, and point out, limitations and regulations. No matter, this is still a huge positive change brought about by hard work from everyone involved. Change can and does happen, but it takes a long, long time.

Thanks to Susan, for bringing this to my attention.

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Water molecules have now been shown to have a fourth “state of matter”

A recent article in “Science World Report” explains how scientists have found a new property of water molecules. A close examination of this information may give new clues as to how a slow sand water filter actually works on the molecular level.  It has been found that water molecules act differently when in microscopically confined spaces such as those which occur in natural environments:

“According to the researchers, such confinements, which are usually 5 angstroms across, are fairly common in nature and occur in environments such as cell walls, mineral interfaces, and dirt.”

In these confined spaces water molecules do not act specifically like solid, liquid or gas.  This may be of interest when determining how slow sand water filters are able to remove some types of petrol chemical contaminants from water, such as PAHs, and THMs.

Hopefully, this above link will remain active for longer than a few days.

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An update on rain water harvesting in Colorado

Colorado appears to be coming around regarding their laws on rain water harvesting.  Its about time given the results of this study which shows that residential home owners catching rain in 55 gallon barrels does not adversely effect the amount of water that makes it to the subsurface. Actually, catching rain water may actually increase the amount of water that makes it to the subsurface; by preventing evaporation. Water caught in a rain barrel is meant to be used – that is – returned to the ground; not hoarded to never be seen again. It looks like Colorado lawmakers finally have come to their senses?

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Urban runoff kills salmon

Update July 18, 2016: Please refer to the comment below by Nat. There is a link to the original study.

Here is a very good reason to set up rain barrels, and slow sand filters. Urban runoff is killing salmon.  It has been known for a long time that urban runoff contains lots of nasty stuff. Common sense tells us that just about anything can be in rain water once it hits the ground. Petroleum, weed killers, herbicides, drugs, chemicals, fertilizers, and anything that people use outdoors will wash off impervious surfaces and will be in urban runoff. That water then runs to the nearest drain and from there right into rivers, creeks, streams, lakes and oceans. If every house had a rain barrel at each downspout, urban runoff during heavy rain events would be reduced, and the water could slowly filter through the soil.  Add to that a slow sand filter, and the water would be cleaned up even more. The article states:

“scientists have mentioned a relatively easy fix that is the filtration through a simple, soil-based system.”

A simple soil based system is essentially a slow sand water filter. We’ve been shouting this out for the past 7 years: slow sand filters clean up water nicely. Others have been saying the same thing.

A copy of the study can be found here

Another article about the same thing is here.



Update October 11, 2015:

Today this article showed up suggesting that 55 gallon barrels filled with, gravel, soil, and compost cleans up the water:

Update October 27, 2015 The link above is no good. 

Here is another link to the same article, captured by another site.

Update February 2016: the above two links are now dead. I cannot find the information they had written. I guess information about urban runoff  poisoning salmon is not very important to some people.


“However regardless of the perpetrator is, the researchers have already got an answer—filter runoff via a fifty five-gallon drum barrel stuffed with gravel, soil, and compost, and the fish survive.” In this quote the author, David Bryan, must mean “regardless of who the perpetrator is”.  The article goes on to state:

“After researchers filtered the water by a 3-foot-excessive soil column containing gravel, sand, compost and bark layers, all the coho survived in addition to they did in clear water.  Exams confirmed the filtration columns lowered heavy metals by fifty eight p.c and polyaromatic hydrocarbons, that are byproducts of gasoline combustion, by ninety four %.”


Update February 19, 2016:  Here is another link to a similar article  regarding urban runoff and salmon; hopefully this one won’t disappear in a few weeks.


I think the author means Polycyclic aromatic hydrocarbons, although they are also referred to as polyaromatic hydrocarbons, but they are most commonly called PAH’s. We tested for hydrocarbons in January of 2010 nearly 6 years ago in one of our slow sand filters. A slow sand filter takes out hydrocarbons. The filter we tested isn’t even 3 feet deep, and it still took out hydrocarbons and harmful bacteria.  Here is another site with information on slow sand filters, (the biosand filter is essentially a slow sand filter with a slightly different design and name, the same principle of operation is used).  There is another site here. Both of these sites have been around longer than ours, and they have plenty of information about slow sand filtration. In fact, this technology has been around for over 100 years. Read about it here.

This is serious stuff. Really! Its just not making national news. This runoff kills salmon in hours. We are continuously allowing toxic water to pollute everywhere. We remove forests, and replace them with blacktop and other types of impervious surfaces, shopping malls, and houses without any thought of the consequences. Now we’re all paying for it. In our neighborhood here,  its not uncommon to see people out in the street at the edge of their front yards with a can spraying the “weeds”. The next week its all brown dead stuff there. Then it rains and all that crap, mixed with tire dust, PAH’s, and oil, runs right down into bear creek, which then runs into Lake Washington. These people should think about it the next time they want a drink of water, or go to that fancy restaurant and order salmon.

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Regarding water, do trees make a difference?

This study, published in 2008, explains how trees in boreal forests help to form clouds. Boreal forests are found in the northern hemisphere. Pine trees, larch trees, and other conifers make up the majority of types of trees found in boreal forests. These trees give off “turpenes” that help to form clouds. Clouds often make rain, and can reflect heat away from the earth. Since rain is essential for rain water harvesting, and we get lots of our water from rain, it might be a good idea to have as many trees around as possible.

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Think about water

An update regarding our ongoing work on slow sand filters. All of the filters here are still working. The oldest, filter 1, is working after 8 continuous years running. Filters 2, 3, 4, and 5 are still working.

Here in Washington state, it has been a hot dry summer, and the fall is starting out dry also. If we get a repeat of last winter’s lack of snowfall retention in the Cascade mountains, there will be major concerns regarding water here in western Washington state.

On another similar topic; the Earth’s ground water is being used up faster than it is being replaced. In areas where there are large aquifers that are used to supply water, this is a huge problem.

It might be a good idea for people to learn about biological sand filtration and rain water harvesting sooner, rather than later. Think about water.  There’s lots of info in this blog about slow sand filtration and rain water harvesting.

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Cryptosporidium in swimming pools

A recent news article has warned of cryptosporidium parasites in pool water.  Another article warns of the same problem. These microbes cannot be removed or killed effectively by the use of chlorine. Ozone is effective but requires high concentrations of the chemical to kill cryptosporidium and the system must be designed specifically for that purpose.

There is an alternative that neither of these articles mentions. Slow sand filtration is the most effective way to actually remove cryptosporiduim from water.

From the EPA site on page 19:

“Of the technologies available to the drinking water industry, membrane processes (forms of micro- and ultra-filtration) appear to provide the most significant levels of Cryptosporidium removal. Conventional treatment practices appear capable of meeting 2-log removals in most of the cases studied to date. Although direct filtration and in-line filtration may be expected to be less effective than conventional treatment, this has not yet been demonstrated in a conclusive manner. Alternative technologies such as diatomaceous earth filtration and slow sand filtration appear capable of achieving comparable, if not better, levels of Cryptosporidium removal than conventional treatment. A comparison of removal efficiencies of some bench-, pilot-, and full-scale water treatment processes is presented in Table 3 below.”

Slow sand filters do not use  chemicals to filter water. They use naturally occurring beneficial non-toxic bacteria that actually eat cryptosporidium microbes and all other dangerous micobes. A slow sand filter is actually a small wetland that purifies water naturally. These filters are inexpensive and require very little maintenance and no added chemicals. They are totally sustainable. This entire blog is about slow sand filtration.  Why aren’t these people using them?

More about cryptosporidium removal here.

and here.

and here (see page 2 of the document) greater than 99.9 percent removal (removal not just killing – ozone or chlorine only kill the microbe)

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Drought conditions declared in Washington state

Back in February of this year we wrote about the lack of snow in the Cascade mountains in Washington state. We hoped for more snow – that did not happen. Now the situation is worse. Let’s hope there is not an extended hot dry summer. Things will get very uncomfortable. For those who have set up rain barrels, the situation may not be as bad. Those who have 3 or 4 rain barrels and a slow sand filter running now will be in much better shape. It’s still not too late to set up a rain barrel or two. . . . .   .

From the Washington state department of Ecology’s website as of May 11: “24 of Washington’s river basins are in a declared drought emergency.”

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A five gallon slow sand water filter

Last year and the year before, we did some work on five gallon slow sand filters.

We set up 3 of them, ran them for a year and a half, and tested the output water. We found that they just barely worked at all. Several issues became apparent. First, the buckets are easily distorted by the weight of the sand. Because of this, if a filter bucket is moved or bumped; the biofilm will be broken and contaminated water will break through to the output. Second, the inside of a new plastic 5 gallon bucket is usually very smooth. This prevents a good seal from forming between the inside surface of the bucket and the sand. The result is that contaminated water slips down the side between the smooth surface of the bucket and the sand. Third; in order to facilitate effective filtration, an extremely slow flow rate must be maintained – much like that of a dripping faucet. Any faster, and the water does not have enough contact time at the top of the sand where the bacterial action takes place.

In the most dire of situations, one of these 5 gallon filters would be better than nothing if all the above issues are taken into consideration. Make sure the inside of the bucket is roughed up considerably, and make sure the flow rate is very, very ,very slow; about 1 litre per hour. Do not disturb the 5 gallon filter container once it is running. Use very fine sand, around .15 mm effective size. Be sure the water put into the filter is non-turbid. Muddy water will NOT work in one of these filters.  If you only have access to five gallon containers, consider using two 5 gallon filters in series. That is put water through one, and then through a second filter of the same size. If you use 2 filters like this, consider using a coarser sand in the first filter; around .35 mm effective size; and then .15 mm effective size in the second filter. Most importantly, know that this will work only marginally at best.

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De-chlorinate water with vitamin C

Chlorine can be removed from water by adding vitamin C to it. This could be a way to facilitate filtering tap water with a slow sand water filter. The chlorine in tap water makes using a biological sand water filter nearly impossible because the chlorine in the water will inhibit the growth of the beneficial bacteria that make a slow sand filter work. If the vitamin c inactivates the chlorine, then the water could be filtered with a slow sand filter.

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