Water Storage Extras: Tank Calculator,
Research Notes on Effect of Tank Materials on Water Quality
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Summary: Download supplements to Water Storage-book: |
Water Storage Extras includes:
Water Tank Calculator (Excel spreadsheet)
Enter diameter, height, roof dome rise of a cylindrical tank with dome roof, get:
- Volume of tank
- Volume under domed roofs of different steepness
Enter thickness of walls, floor, and roof, get:
- Amount of material (for ordering concrete, sand, cement for ferrocement tanks)
Enter density of material, get:
- Load on ground under tank
Enter rebar hoop spacing and diameter, get:
- Hoop stress at bottom of tank for ferrocement tanks
Also includes calculator for determining cost of materials for ferrocement tanks.
Download tank calcluator now (Microsoft Excel spreadsheet, 96 KB)
Research notes on materials leaching, bacterial regrowth, disinfection by-products, permeation
30 pages of research abstracts in editable MS word outline and PDF format.
This material is barely formatted and not edited, or synthesized; it is our sorted but raw research notes. There is a lot of fascinating, confusing reading in here—plenty of contradictions, not much clarity, plenty of food for thought and indication of future research critically needed. Why doesn't anyone know if storing water in PE tanks is safe? There's about a million of them in use...
Download research notes now (Microsoft Word document, 288 KB)
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Water Contamination Research Collected Notes on Toxics Leaching from Plastic, Metal and Cementations Containers, Bacterial Regrowth, and Disinfection Byproducts Art Ludwig November 18th, 2004 HYPERLINK "http://www.oasisdesign.net/water/quality/toxins.pdf" http://www.oasisdesign.net/water/quality/toxins.pdf Water Quality Standards National Primary and Secondary Drinking Water Regulations HYPERLINK "http://www.epa.gov/safewater/mcl.html" http://www.epa.gov/safewater/mcl.html HYPERLINK "http://www.ehso.com/ehshome/DrWater/drinkingwaterstds.htm" http://www.ehso.com/ehshome/DrWater/drinkingwaterstds.htm National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards protect drinking water quality by limiting the levels of specific contaminants that can adversely affect public health and are known or anticipated to occur in public water systems. Table 1 divides these contaminants into Inorganic Chemicals, Organic Chemicals, Radionuclides, and Microorganisms. See Setting Standards for Safe Drinking Water to learn about EPA's standard-setting process. Follow these links to download copies of National Primary Drinking Water Regulations and National Secondary Drinking Water Regulations. National Sanitation Foundation. 2001. NSF Standard 61 Drinking Water System Componentsó Health Effects. ANSI/NSF Standard 61. National Sanitation Foundation International. General and Misc Water age Population Served Miles of Water Mains Range of Water Ages within System (Days) Method of Determination 750,000* 1,100 <1 ñ 3 Fluoride Tracer 800,000 2,750 3 ñ 7+ Hydraulic Model 87,900* 358 > 16 Chloramine Conversion 24,000 86 12 ñ 24 Hydraulic Model Tank materials for aquaculture HYPERLINK "http://www.teamaged.org/aquaculture/ctanks.htm" http://www.teamaged.org/aquaculture/ctanks.htm glass or acrylic plastic - Used to construct aquaria. While aquaria are under rated, these are an excellent option for teachers with or without a budget (everyone has one in their attic, garage, or cellar) or a lot of class space (can provide students with individualized learning and entrepreneurial opportunities). fiberglass - Tanks are easy to build, modify and repair; pre-fabricated tanks can be purchased in a large range of sizes and shapes; can be expensive. treated plywood, cement blocks or galvanized steel - Tanks are easy to construct and can be a cheap alternative; cover with a non-toxic liner material (do not use liners treated with fungicide e.g., pool liners) or paint with water proof epoxy paint. epoxy coated steel - Expensive. poured cement (e.g. casket liners, old septic tanks) - Potential to find some good bargains, but tough to move. polytanks - Considered short term tanks; good (fairly cheap) for classroom aquaculture. stainless steel (e.g. unused milk bulk tank or cheese vat) - Expensive. porcelain bonded carbon steel (e.g. discarded silo rings) - Nice if available for free. Q: How does lead get into drinking water? A: Lead isn't in water that leaves our treatment plants. However, it might occur in your home's plumbing. Lead levels in your drinking water are likely to be higher if: ï Your home has faucets or fittings made of brass that contain some lead; ï Your home or water system has lead pipes; ï Your home has copper pipes and the house was built from 1982-87. If your interior plumbing fits one of these categories, you have an increased risk if you have a water softener or water often sits in pipes for several hours. Q: What are lead's health effects? A: Lead is a toxic metal that is harmful to human health if inhaled or swallowed. It is a health concern in drinking water at levels above 15 parts in a billion. (One part per billion is equivalent to a single drop of water in 55,000 gallons.) Although it must build up in the body before it affects one's health, elevated levels attack the brain, kidneys, nervous system and red blood cells. The degree of harm depends upon the level of exposure from all sources, including soil, wind and water. Effects range from subtle physical changes at low levels to severe neurological and toxic effects or even death at extremely high levels. Water Purification Methods * Boiling Most water can be purified for drinking purposes by boiling it for 10 minutes. This will destroy the bacteria. In order to improve the taste it will be necessary to aerate it after boiling. This is accomplished by pouring it from one container to another several times. This should be done after the water has been allowed to cool. * Chlorination For long-term storage, water should be sterilized or disinfected. Water stored in thoroughly cleaned plastic or glass containers can be chemically disinfected for long-term storage by treating each gallon with sixteen drops of liquid chlorine bleach (Clorox or Purex type bleaches, containing 4% to 6% sodium hypochlorite). One teaspoon of bleach disinfects five gallons of water. This level of treatment will prevent growth of microorganisms during storage. After adding the proper dosage and stirring, allow the water to stand for 30 minutes. It should then have a distinct odor of chlorine. If this odor is not present, add another dose of the solution and let stand for another 15 minutes. The taste or smell or chlorine in water as treated in this manner is a sign of safety. It is not harmful. On the contrary, if you cannot detect chlorine in water you are trying to purify by this method, do not drink it. * Purification Tablets Tablets that release iodine may be used safely to purify drinking water. These tablets can be found at most drug stores and sporting goods stores. The names vary but it is generically known as halazone tablets. Follow the directions on the package. Usually one tablet is sufficient for one quart of water. The dosage is doubled for cloudy water. * Iodine Ordinary Household Iodine may be used to purify small quantities of water. Add 2-3 drops of Tincture Of Iodine to each quart of clear water (8-10 for cloudy water). Mix & allow to stand for 30 minutes. This page created by: HYPERLINK "mailto:peter@coolpages.net" peter@coolpages.net HYPERLINK "http://coolpages.net/2000/" http://coolpages.net/2000/ Emergency Water storage HYPERLINK "http://www.storablefoods.com/water_storage.html" http://www.storablefoods.com/water_storage.html NOTE: The easiest way to store the bulk of your water is in 55 gallon polyethylene (plastic) water drums (FDA approved for storing drinking water). You simply fill the drums up with your own tap water. The drums offered by 21st Century Food Storage are the best industry has to offer, and are designed to have weight stacked on them when filled with water, this allows you to stack your food on top of them and save space while keeping your food and water together. We recommend two 55 gallon drums of water per person, this along with collecting "rain" water should be suitable. Before filling a drum with water, make sure the NPT plug (fine thread; non-white cap) is not positioned next to a wall etc. It should be on the top front side of the drum for easy access, because this is the bung hole that the drum pumps thread into. Remember also that you have several sources of water already in your home that can be tapped in an emergency such as your hot water heater, toilet tanks (don't use water from a tank that contains colored disinfectant, it is poisonous), water pipes, ice in the freezer, etc. Water is relatively inexpensive to store and certainly not difficult to do - but certainly the time to store is now. It is also a good idea to have a water filter in addition to your water storage drums. This would allow you to purify dirty water from lakes, rivers, creeks, etc. 21st Century Food Storage offers The British BerkefeldÆ Emergency Water & Camping Filter - the original gravity filtration system used by thousands of missionaries worldwide. No water pressure or pumping required. High tech ceramic filter system. Time tested for over 140 years. The "Super Sterasyl" filters reduce up to 99.99% of particulates, cysts, parasites and pathogenic bacteria. See "Water Filtration" in our on-line store for details. DISINFECTION: For long-term storage, tap water should be sterilized or disinfected in thoroughly cleaned plastic or glass containers. Water can be chemically disinfected for long-term storage by treating each gallon with 16 drops of liquid chlorine bleach (Clorox or Purex type bleaches, containing 4% to 6% sodium hypochlorite; do not use scented bleach). One teaspoon of bleach disinfects five gallons of water. Three tablespoons will disinfect 55 gallons of water. This level of treatment will kill bacteria and viruses and prevent the growth of microorganisms during storage. Also check with your local water plant for any additional information they may have for you. Water stored in plastic containers should not be stored near gasoline, kerosene, pesticides or similar substances. Vapors from these substances could permeate the plastic and affect the water. Thick-walled polyethylene containers are significantly less permeable to vapors than are thin walled containers. Be certain, when selecting a storage container for water, that it has a tight fitting cap or lid to prevent entrance of contaminants and evaporation of water. Because sunlight has an adverse effect on plastic, water should be stored away from direct exposure to sunlight. Store in a cool, dry area with no sunlight, like the basement. Studies show sterilized or disinfected water, stored in clean, food-approved containers with secure lids or caps should be safe for use even after many years of storage. Replacement of stored water with fresh water should be necessary only if the stored water becomes contaminated in some way or if the container should begin to leak. Be certain to label each container so there will be no question about its contents. Include the date and information on the method of disinfection used. We recommend changing properly stored water every three to five years. Coatings HYPERLINK "http://www.epa.gov/safewater/tcr/pdf/storage.pdf" http://www.epa.gov/safewater/tcr/pdf/storage.pdf tank Turnover ñno stagnant water 2.1.4 Chemical Contaminants Coating materials are used to prevent corrosion of steel storage tanks and to prevent moisture migration in concrete tanks. Through the 1970's, coatings used in finished water storage facilities were primarily selected because of their corrosion resistance and ease of application. This led to the use of industrial products like coal tars, greases, waxes and lead paints as interior tank coatings. These products offered exceptional corrosion performance but unknowingly contributed significant toxic chemicals to the drinking water. Grease coatings can differ greatly in their composition from vegetable to petroleum based substances and can provide a good food source for bacteria, resulting in reduced chlorine residuals and objectionable tastes and odors in the finished water (Kirmeyer et al. 1999). An old grease coating on a storage tank interior in the state of Florida was suspected of causing water quality problems in the distribution system such as taste and odor, high chlorine requirements and a black slime at the customers tap. The Wisconsin Avenue 500,000 gallon elevated tank was originally coated with a petroleum grease coating when it was built in 1925. In 1988, the storage facility was cleaned and the grease coating was reapplied. In 1993, a tank inspection revealed that the grease had sagged off the tank walls and deposited a thick accumulation of black loose ooze in the bottom bowl of the tank (6-8 inches deep). A thin film of grease continued to coat the upper shell surfaces. Although this material had performed well as a corrosion inhibitor, it was introducing debris into the distribution system as well as creating a possible food source and environment for bacteria. The City decided to completely remove the grease and reapply a polyamide epoxy system. This work was completed in 1996 (Kirmeyer et al. 1999). Since the tank was returned to service, water quality has markedly improved. The required chlorine dosage rate has decreased from 4.0-5.0 mg/L to 3.5 mg/L. The chlorine residual at the tank outlet has improved from <1.0 mg/L to 1.4 mg/L. No more ìblack slimeî complaints have been received. Epoxy There is evidence that epoxy coatings leach various organic additives into water. ìPermeation and leachingî http://www.epa.gov/safewater/tcr/pdf/permleach.pdf The rate of leaching of organic additives was found to decrease exponentially with time. Therefore, it is recommended that newly lined pipes be pre-soaked prior to release to service. Normal hydrostatic testing and disinfection activities will help remediate leaching. Extending the curing process will also help improve the stability of epoxy linings Leaching from metals Lead HYPERLINK "http://www.denverwater.org/waterquality/pbwater.html" \l "Where" http://www.denverwater.org/waterquality/pbwater.html - Where Brass faucets can legally contain as much as eight percent lead by weight. Solders and flux are considered lead free when they contain not more than .2 percent lead. Before 1987, solder normally contained about 50 percent lead. Always use cold water for food and beverage preparation. Hot tap water can leach higher amounts of lead or other metals from plumbing or the hot water tank. If you're concerned about elevated lead levels in your water, run the tap until the water becomes colder before using it. Remember to catch the flushed water for plants or other household use. Aluminum Aluminum Toxicity: Issues and Insights http://www.bayeralbumin.com/web_docs/WP_Aluminum%20Toxicity.pdf ìPeople are continuously exposed to Al by ingesting water, food, and dust particles. 2 Estimates suggest that adults consume approximately 3 to 5 mg of Al in their daily diet. Healthy individuals can easily handle normal Al intake, since absorption in the gastrointestinal (GI) tract is low. 4 The GI tract provides efficient protection against Al absorption, and it is estimated that less than 1% of ingested Al is absorbed by the body. 5 In fact, healthy individuals have very low levels of Al because the GI tract, skin, and lungs are effective barriers to Al absorption, and the kidneys efficiently eliminate absorbed Al by excretion.ì People who are at risk from aluminum poisoning: Dialysis patients and others with impaired renal function Newborns and premature infants The elderly Patients receiving TPN Burn patients Effects of aluminum toxicity: Associated: Dementia Encephalopathy Learning deficits Possibly associated: ALS Parkinsonís disease Alzheimerís disease Report of the New South Wales Chief Health Officer, 1997 http://www.health.nsw.gov.au/public-health/chorep97/env_watalum.htm Drinking water probably contributes less than 5 per cent of the total human intake of aluminium. Although some studies have suggested a tentative link between aluminium and Alzheimerís disease and dementia, the evidence as a whole does not support a causal association. Accordingly, there is no health-based guideline for aluminium in water. Copper acidic water can deteriorate copper pipes. http://www.boston.com/globe/search/stories/health/how_and_why/041596.htm]
"http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9641831"
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9641831
The containers of mineral water and the foreign plastic substances which were
found in the mineral water were investigated. Most of plastic bottles were made
of polyethylene terephthalate (PET) and the caps were made of polypropylene
(PP), polyethylene (PE) or aluminum. PE liners were attached to some caps. Most
of the foreign plastic substances were PET while others were PE, PP, Teflon
and rubber. Some bottles had a scratch on the top inside. The origin of most
PET fragments was presumed to be scraped off the bottles by the lowering of
the injection nozzle during the water filling process. The sources of the other
substances were also determined. Chemical and in vitro toxicological evaluations
of water packaged in polyvinyl chloride and polyethylene terephthalate bottles.
Sauvant MP, Pepin D, Bohatier J. Faculte de Pharmacie, Laboratoire d'Hydrologie
et Hygiene, Clermont-Ferrand, France. HYPERLINK "http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7589720"
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7589720
This study proposed a new strategy assessing the health risks of mineral water
packaging and compared the chemical analytical techniques and some in vitro
cytotoxicological assays for the study of PVC and PET materials at the main
stages of the manufacturing process of bottles. These evaluations were carried
out with food simulant (deionized-endotoxin-tested water) and with natural mineral
water in real conditions of packaging and storage (from 0 to 24 months). The
complementarity of these two approaches is discussed. Some analytical and cytotoxic
abnormalities were detected in the food simulant after contact with the batches
of powdered PVC compound, PET resin and their intermediate steps of transformation
(PVC-'paraison', PET-'perform'). But these results did not reflect the actual
behaviour of the finished PVC and PET bottles, for which no major abnormality
was detected in the natural mineral water. The bacterial flora of non-carbonated,
natural mineral water from the springs to reservoir and glass and plastic bottles.
Bischofberger T, Cha SK, Schmitt R, Konig B, Schmidt-Lorenz W. Institute of
Food Science, Swiss Federal Institute of Technology, Zurich. HYPERLINK "http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2223521"
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2223521
Quantitative and qualitative determinations of the bacterial flora of non-carbonated
natural mineral water at the most important steps during bottling at a large
water source yielded the following results: (i) Colony counts (on 1:10 diluted
plate count agar, incubated at 20 degrees C for 14 days) for water of the five
springs and the mixed water were less than 1 to 4 cfu ml-1. The Gram-negative
bacterial flora (n = 50 isolates) showed a very different but constant spring
specific species distributions with predominance of either eutrophic fluorescent
pseudomonads, oligotrophic non-fluorescent pseudomonads or oligotrophic yellow
bacteria. (ii) In the reservoir and immediately after bottling the counts were
in the range of 10 cfu ml-1. But nearly 30% of the species of the spring water
were no longer detectable and there was a significant increase of Gram-positive
bacteria. (iii) After 1 week of storage at 20 degrees C colony counts of more
than 10(5) cfu ml-1 were found in plastic bottles, but only about 10(4) cfu
ml-1 in glass bottles. Besides, a very distinct change of the composition of
the microflora occurred. In glass bottles slow-growing oligotrophic non-fluorescent
pseudomonads, yellow bacteria and Acinetobacter predominated. In plastic bottles
fast-growing eutrophic and mesotrophic fluorescent pseudomonads, Flexibacter
and Acinetobacter were dominating. In mineral water, bottled into thoroughly
cleaned glass bottles, colony counts of more than 10(5) cfu ml-1 were found
within 4 days. In bottles, cleaned mechanically as usual, the increase was significantly
slower with a maximum of only 5 x 10(3) cfu ml-1 after 8 days. The results of
inoculation experiments in sterile filtered mineral and distilled water led
to the suggestion that the difference between the two types of bottles is caused
firstly by an inhibition of growth due to residues of cleaning detergents in
the glass bottles. Growth promotion by dissolved organic substances in the plastic
bottles only played a minor role. After repairing of the pump at a depth of
300 m in a warm mineral water spring, the colony counts at 20, 37 and 42 degrees
C on 1:10 diluted and normal plate count agar increased beyond the limits required
by the EC directive for mineral water stored a month. Then colony counts decreased
slowly and reached the initial level after 1 year, except for the colony counts
1:10 diluted agar at 20 degrees C which stabilized at a relatively high number
and a significant alteration of the microflora.(ABSTRACT TRUNCATED AT 400 WORDS)
Donít worry about it-Plastics Council HYPERLINK "http://www.newton.dep.anl.gov/askasci/chem00/chem00959.htm"
http://www.newton.dep.anl.gov/askasci/chem00/chem00959.htm All the plastics
coded 1 through 7 can be made in grades that are approved for use as food containers.
You do not really need to worry about the leaching of chemicals from the plastics.
Even the plastics that can exude some components upon prolonged content do so
in such low amounts that it is not a health issue. The chance of being injured
by a car as you are on your way to the store to buy bottled water is much, much
greater than the chance that your health will be impaired by drinking water
from a plastic container. Richard E. Barrans Jr., Ph.D. PG Research Foundation,
Darien, Illinoi Leaching from fiberglass Leaching of organic contaminants from
GRP pipe http://www.fwr.org/waterq/dwi0032.htm A wide range of contaminants
were found to leach into drinking water from GRP pipe including a range of phthalates
and styrene. The leaching rates were appreciable although depletion with time
would be expected. Leaching off substances from products used in contact with
water intended for human consumption HYPERLINK "http://www.dwi.gov.uk/cpp/pdf/protocol1.pdf"
www.dwi.gov.uk/cpp/pdf/protocol1.pdf