Hi all,

Short question version:

What are the most effective means of filtering and purifying water on a daily basis from rain runoff in a coastal areas?

Long question version (with background context):

My aunt and uncle are building a house on a cay ("key") in a Basque providence of Spain (I believe) and asked me about what I knew about water purification systems for use on an everyday basis. They have spoken to the locals and apparently the primary source of water is bottled water for drinking and rainwater runoff into collection barrels at each house for other needs (so desalination is not necessary). Since bottled water is prohibitive in cost and has environmental issues they have decided to explore filtration and purification systems.

The runoff water typically contains dust and bird feces and is stagnant. I recommended general ecology as a good residential brand and/or perhaps Berkey ceramic filters paired with chemical purification as a more cost effective option. However, I am definitely no expert and I lack authority in this area and I could only recommend based on my experience with filters I have used in the past for much different applications. I tried searching the ETS forums for previous postings on this topic but had no luck. Thus I wanted to ask my friendly community of ETS members their opinion and expertise in this area:

What are the most effective means of filtering and purifying water on a daily basis from rain runoff in a coastal areas?

Thank you "all y'all" as my aunt and uncle would say.

Cheers,
Nemo

Two good links at the start of this old thread.

Thanks Tom!

Do you have a good method you could lend me for searching the forums?

I'll ask my aunt and uncle if they have a type of cistern system being built currently.

Cheers,
Nemo

Nemo,

Another good thread on the subject is here. Start at the top of the thread and work your way down.

-Blast

Thanks Blast!

Great info on that thread! Guess I should just scroll through the titles of topics in the future to find these gems. I also just heard about this site on the radio for cooking food and pasteurizing water.

Cheers,
Nemo.

I recently read in a book on rainwater collection that rainwater has only 1/20th (5%) of the contaminants that groundwater has.

The main problem is preventing contaminants from getting into the rainwater to begin with.

One way to keep birds from perching on the ridgeline of a building is to stretch a stainless steel wire about an inch or two above it.

One good book on rainwater collection is Water Storage: Tanks, Cisterns, Aquifers and Ponds by Art Ludwig. (Who also has a few good books on greywater).

Another is Rainwater Harvesting for Drylands: Vol. 1 Guiding Principles by Brad Lancaster, first in a trilogy. Volume 2 is Water-Harvesting Earthworks, and Vol 3 is Roof Catchment and Cistern Systems, which may not be out yet.

Sue

Some friends of mine lived in Australia for a few years and used
a rooftop cistern for all their water. The wife of the couple is a
hydrologist and did frequent testing of the water. Only in the first
rain of the season did contamination of any consequence occur. They
were in an arid part of the country.

On the subject of filtration, an inexpensive method is a biosand
filter. The schmutzdecke layer of biological material that forms
on the top will eat up heavy metals, bacteria, virus, etc to a high
degree.

http://en.wikipedia.org/wiki/Slow_sand_filter

I have a friend who started this organization for household
bio-sand filters for people in Haiti.
http://cleanwaterforhaiti.org/Design/HTML/filter.html

He works here
http://www.cawst.org/
and you can go take a training class from them.

Thank you Susan and Clearwater,

I'll fwd your recommendations to my aunt and uncle. I have heard about the biosand approach on the radio in a segment NPR did a few years back. It appears to be the most cost effective and the most sustainable way to approach water filtration.

Cheers,
Nemo