In field observations, the raw and clean water tanks have been found to have solids (calcium, magnesium, mud, etc.) settle to the bottom over time. This sediment is caused by normal precipitation of the dissolved and suspended solids in the raw water. This residue can be disturbed and become suspended solids when the water tanks are refilled after being drawn completely down. This sediment buildup can introduce turbid water into the system with very high levels of suspended solids that are not caught by the trash filter or that may enter the filters during the transition phase of operation on standard ozone systems. This situation results in the 5.0 micron filter being clogged rather quickly and prematurely by the accumulation of these solids on the surface of the filter. These particles are too large to be drawn immediately into the interior of the filter.

In one instance, due to the lack of a replacement filter, it was discovered that the surface of the 5.0 micron filter could be cleaned and placed back in service with little or no degradation of its efficacy. This will, of course, depend on the size and type of the suspended solids.

Living Waters and manufacturers’ documentation indicate that the 5.0 micron filter cannot be cleaned. This is true for clogging of the interior of the filter, but if the contamination is concentrated on the filter surface, cleaning may be possible.

The following protocol should be followed when cleaning the 5.0 micron filter due to suspended solids contamination on the surface of the filter:

1. Examine the trash filter and water tanks for suspended solids and turbidity. Flush the tanks and lines if necessary.

2. Clean the trash filter thoroughly including the canister using the existing protocol.

3. Clean all sediment from the water tanks and establish a regular schedule to check the tanks for sediment and flush as necessary.

4. Flush the lines from the tank to the trash filter and the return line from the clean water tank

5. Prepare a 5 gallon bucket half full of clean, chlorinated water.

6. Remove the 5.0 micron filter. Exercise caution in handling the filter as it could contain a concentrated level of contaminates. It should be treated as infected and a biohazard. Use rubber gloves, if available.

7. Place the filter into the bucket of chlorinated water. The chlorine will reduce the efficacy of the activated charcoal (if any) in the filter cartridge.

8. Using a soft plastic brush, gently brush the accumulated solids from the surface of the filter until it is visibly clean.

9. Empty the bucket and repeat this process until the water in the bucket remains clear.

10. Rinse all visible residues from the 5.0 micron filter canister.

11. Install the cleaned filter and resume normal operation observing G1 to insure that the filter is no longer clogged (compare G1 to the last operator log reading prior to the filter clogging). If the G1 pressure level has not dropped substantially, this will indicate that the interior of the filter is clogged and the filter must be replaced.

12. Disinfect the bucket, brush, and all surfaces contacted by the filter during the cleaning process and safely dispose of the cleaning water and gloves.

13. Wash your hands thoroughly after this procedure using soap and chlorinated water. Use hand sanitizer, if available.

Contributed by Jerry Goode.

We have seen a condition similar to this at CWU and it usually indicated that the electrical connection with the UV Lamp was at fault.  Specifically, the problem was with the ground lead in the connection.  Once a tight connection was made, the problem was corrected, and the beeping stopped.  In these cases, the red light stayed lit during the beeping indicating that the UV was not providing disinfection protection.

In the Guatemala report, the UV Unit continued to beep even though the green light stayed lit.

A check of the TrojanMax web site discovered the following:

“Trojan UV Max C4 System Beeping After Replacing Lamp, Power Supply Issue
If you have a Trojan C4 UV Max power supply (black box with two LED light indicators) that was installed between January 2009 and January 2010, it is possible that it could have an alarm fault and will not reset.
The problem occurs when the Trojan UV lamp has been installed for about 1 year.  After 1 year, the UV Unit will start beeping indicating it is time to change the UV lamp and quartz glass sleeve.  After replacing the Trojan lamp there is no way to reset this alarm, and the unit will just keep beeping. 

 Trojan will swap these with an upgraded power unit at no charge. You can contact Trojan directly via their website or toll free line 1-800-265-7246.”

LWW is in the process of checking their stock of Trojan C4 UV Max units to see if they were manufactured during the time in question.  As we find these units, LWW will contact TrojanMax to replace them.

We ask that all Initiating Partners with UV systems purchased from FCI alert their Operating Partners, so that they can take action to correct this problem.  We have alerted our In-country Coordinators, Claudia and Miriam, so that they will know how to respond.

The good news is that as long as the Green Light stays lit on the unit, it will continue to disinfect the water and protect the users.

If you have any other comments or questions, please contact LWW at

infolww7629@livingwatersfortheworld.org

The dense zeolite material increases the media loading factor 2.8 times the loading factor for sand. In a typical barrel sand filter, for example, 2 – 3 cu ft (150 lbs) of media can be used in place of sand to get better filtering efficiency with more flow rate through the filter. At a price of $50 – $60 per cu ft, the media is more expensive than sand, but worth the efficiency and flow improvements.

In pressure filter applications, higher flow rates will improve particulate removal over sand in most cases.

LWW has identified zeolite media suppliers in the Yucatan and Guatemala. The next time you are considering installation of a barrel sand filter, think about using zeolite media in place of sand.

Here’s a link: www.turbidex.com

In this segment, we will focus on the water quality standards that Living Waters for the World (LWW) follows when evaluating a particular raw water source.

When evaluating a raw water source, LWW uses the Guidelines for Drinking-water Quality, Third Edition, Volume 1, Recommendations published in 2004 by the World Health Organization (WHO) as the standard. This volume is an excellent reference for hundreds of water contaminants found all over the world. The book is divided into section covering microbial aspects, chemical aspects, radiological aspects, and acceptability aspects of defining the quality of a water sample.

In some cases such as Arsenic and Nickel, the WHO Guidelines are provisional guidelines that have not been adopted by WHO. In these cases, LWW may revert to using US EPA Guidelines for Drinking Water or follow the provisional guidelines.

The chart below provides a comparison of WHO Guideline values, US EPA Primary Drinking Water Standards, and the detection and reporting limits for Test America.

Note that each of the Guideline Values is greater than the detection level providing confidence that the level of the contaminant can be measured and a determination of the quality of the water can be made based on the analysis.

Also note that the WHO guidelines for Mercury, Selenium, and Lead are less than the US EPA guidelines.
Using the water analysis from the previous posting, the Lead contamination is less than the WHO Guideline value. (1.5 ug/L = 0.0015 mg/L < 0.01 mg/L WHO)

The results are similar for Arsenic (2.0 ug/L = 0.002 mg/L < 0.01 mg/L WHO)

Metal tested Result Qualifier RL MDL Units
Lead 1.5 U 1.5 0.50 ug/L
Arsenic 2.0 J 2.5 1.3 ug/L

Interpreting water quality testing results can be challenging. It is most important to pay attention to the units in the report be they ug/L or mg/L. As long as the units are consistent, then comparison of the various values is straightforward. In case there are any questions, you may contact Living Waters for the World for assistance.

The key to interpreting any test results is understanding the abbreviations and other qualifiers listed on the sample results page. Not every test method is created equal. Each test method has a limitation on the minimum concentration that can be measured. The following qualifiers outline those limitations.

The MDL is the Method Detection Limit. If the concentration of a metal, for example, is above the MDL, then it will be detected by the test. If the concentration is less than the MDL, then the test will not detect it.

RL is the Reporting Limit for the test method. In many cases, the test method may detect the presence of a metal in the sample, but the concentration will be too small to trust the measurement. The RL sets the minimum concentration where the reported result can be trusted as valid.

The following qualifiers are qualifiers that are listed on all Test America reports. These qualifiers are particularly important when interpreting the results from metals testing.

A “U” qualifier indicates the analyte or metal was analyzed for but not detected in the sample.

A “J” qualifier indicates the result was less than the Reporting Limit (RL), but greater than the Minimum Detection Limit (MDL). The reported result is an approximate value.

In the following table, the Lead analysis was reported as 1.5 ug/L, but with a U qualifier. The U qualifier means that no Lead was detected in the sample! The result is reported as 1.5 ug/L because that is the Reporting Limit (RL) of the test method.

In the case for Arsenic, the result was 2.0 ug/L concentration in the sample. This result is qualified with a J because it is below the Reporting Limit (RL), but above the Minimum Detection Limit (MDL). The test report will also note that 2.0 ug/L is an approximate value.

As in all test reports, it is important to note the units of measure for each reported result. The results above are concentrations reported in micro-grams per liter (ug/L) of sample. This also translates to parts per billion (ppb).

Some results are concentrations reported in milli-grams per liter (mg/L) of sample. This also translates to parts per million (ppm). 1 ppm equals 1,000 ppb.

When comparing your results to any of the World Health Organization (WHO) guideline values for drinking water, make sure that all the units are consistent. In the next blog posting, we will take a closer look at these WHO Guideline values.

Demonstrated in the photos below, the Ozonator Observation Hood allows students to observe the “blue-green glow” of the lamp cartridges under any conditions.

Blue-green glow of ozonator lamps

This innovation may not be as cool as the “Woehler/Advent Rinse Assembly” found in Appendix C of Volume 4 of the handbook, but it may help out as you train your Operating Partners on how the Ozonator works.

FCI will not be stocking the Ozonator Observation Hoods any time soon, so you are on your own as far as using this in your systems.

Let the clean water flow!

Contributed by Dave Parks and Ralph Young

The situation went undetected till someone, while preparing  for an international trip, noticed the contents of the pillow packs were white instead of golden colored. They contacted LWW, and we tested the whirly packs only to find that indeed the wrong pillow packs were in the kits.

When we checked with some teams who had received the packs, they commented they thought it unusual the kit had been changed and even more unusual that all their tests came back negative for bacterial contamination, noting that from the start, “the test didn’t look right.” (In the photo below, the faulty whirly pack tests stayed clear and did not turn the golden amber color as expected).

Ultimately, if something doesn’t look right or feel right with a test, contact LWW immediately so we can ascertain if there is a problem – in the case of the whirly packs, people’s health may have depended on it.

There are a lot of numbers to consider but here was my response to the IP.

The US EPA MCL for Fluoride is 4 mg/L.

The WHO guideline value for drinking water is 1.5 mg/L.

The proposed US EPA standard for drinking was is 0.7 mg/L.

Many municipalities add Fluorine to their drinking water to a level of 1.0 mg/L.

The health effects as quoted from the WHO Guidelines for Drinking Water (2004) are “Exposure to excessive consumption of fluoride over a lifetime may lead to increased likelihood of bone fractures in adults, and may result in effects on bone leading to pain and tenderness. Children aged 8 years and younger exposed to excessive amounts of fluoride have an increased chance of developing pits in the tooth enamel, along with a range of cosmetic effects in  teeth.”

The WHO health impacts are “…concentrations in drinking-water may give rise to dental fluorosis in some children, and much higher concentrations may
eventually result in skeletal damage in both children and adults. “

“It was also recognized that in areas with high natural fluoride levels, the guideline value may be difficult to achieve in some circumstances with the treatment technology available.  It was also important to consider climatic conditions, volume of water intake and intake of fluoride from other sources.”

I think the bottom line here is that a fluoride level of 2.2 mg/L will not be adverse to the health of adults and children consuming this water. Most of these standards have a safety factor applied to them and a level that is below the US EPA maximum contaminant level of 4.0 mg/L would be acceptable.

As a cautionary note, they should probably have their water tested quarterly or
every 6 months for fluoride to see if anything has changed. Should the levels
increase, then they should consider another water source.

Here’s a link:  http://water.epa.gov/drink/contaminants/basicinformation/fluoride.cfm

Was this good advice or is there something else that should be considered?

Your comments are most welcome.

Please note that the disinfection option for a Standard System with hard water as its source must be ozone.  UV equipment manufacturers do not recommend UV disinfection if the water hardness is greater than 120 ppm.

In some cases, the water analysis for a site indicates that ROS technology is needed, but the partners agree that they cannot justify a more expensive and complicated ROS system.  In these cases, partners may ask LWW what measures might be taken to mitigate the long term adverse effects of hard water on their clean water system.

So what measures might a LWW Team consider when installing a Standard Clean Water System where the source water has a hardness greater than 220 ppm? 

1.  Venturi – have a spare

Because the venturi is the most vulnerable component in the Standard Ozone System, LWW recommends having an extra venturi on site from start-up.

2.  Instrumentation – More pressure gauges and a water flow meter

Added instrumentation on the system is also recommended.  Having a
pressure gauge on each filter is suggested as well as having a water flow meter
installed before the venturi.

3.  Instrumentation – Air flow meter

A meter to measure the air flow through the ozonator is recommended.
This flow will be between 0 and 20 standard cubic feet per hour (SCFH).

4.  Protected/shaded raw water tank

The raw water tank should be shielded from overheating in the sun.

5.  Raw water feed from the tank – several inches above the bottom

The tank should be configured such that the water feed is not off the bottom of the tank.  There should be two take-off points on the tank, one several inches above the bottom for water feed and one at the bottom to remove accumulated sediments.

6.  5.0 micron Big Blue Filter without carbon

LWW recommends that the 5 micron Big Blue filter not be the carbon impregnated filter.  This filter will be the first to foul and will need to be replaced more frequently than 1x per year.  The outside or surface of the 5.0 micron filter should also be inspected for sediment buildup and cleaned as needed.  The 0.5 micron Big Blue filter should continue to be the carbon impregnated filter.

7.  Use more unions to increase component access

Because the system will have to be inspected for scale and cleaned out more often, the team recommends that all equipment and pipe runs in the churn be installed with unions to isolate it and make removal easier.

8.  Additional instruction and training

Extra instruction will be needed to emphasize the importance of data collection and recording.  Hardness in the raw water will have a negative impact on the performance of the system.  In order to identify these trends before it is too late, data will need to be recorded, trended, and analyzed.  Good communications between the partners will be important to ensure that data is not lost and that problems are identified and corrected in a timely manner.

Contributed by Ralph Young

The internal check in the venturi is shown in the picture below.  The failure mode is not certain, but the rubber disk probably gets stuck in the open position allowing water to flow back through the tubing.  Ths can be confirmed when water is observed leaking out the venturi air connection nipple.

Rubber disk check valve

In order for the failure to damage the ozonator lamp cartridge, the Kynar plastic check valve or the older gray PVC spring-loaded check valve must fail.  Several years ago, the PVC check valve was replaced with a more reliable low-pressure plastic check valve.

Kynar Plastic Check Valve on the left

LWW recommends that the air/ozone tubing be run to a point higher than the churn when connecting to the ozonator.  The plastic check valve should be at the highest point in the loop.

In the event your Operating Partner observes water leaking out the venturi and into the tubing, the following corrective action can be taken:

1.  Replace the venturi, if you have a spare.  LWW does not recommend taking the venturi apart to troubleshoot and replace the internal rubber disk check valve.

2.  If you do not have a spare venturi, you can modify the operating procedures to disconnect the air/ozone tubing at the venturi at the end of every batch.  Water can be drained from this leg of piping to relieve any internal pressure on the venturi.

3. LWW is investigating installing a valve in the tubing in order to isolate the venturi from the ozonator.  At the end of each batch, this valve should be closed.

If you have any suggestions or troubleshooting tips, please post them.