Preservation of the LWW System Board

This article was contributed by Tom Ritter.

As our LWW systems age, our Operating Partners (OPs) have found that the plywood board used for mounting components may need some attention.  All LWW system boards should be painted on both sides and all edges before installing a system.  Some OPs, however,  still experience deterioration of the board over time.

The latest method suggested by Tom Ritter and his team working in El Salvador is to attach one to four treated 2″ x 4″ boards vertically to the concrete wall.  After painting, they  coat and treat the plywood system board with polyurethane varnish – front, back, and edges.  Once the board dries, they mount the system board to the wall on the 2″ x 4″ supports.  By mounting the board in this manner, they create space for air flow behind the board and get the full benefit of the polyurethane treatment.

One of the consequences of this procedure is the extra drying time for the board after it’s been treated.  Teams will need to program additional drying time as well as find a local source for polyurethane varnish.  Sometimes using a hair dryer can speed up the drying time.

Please feel free to share your ideas by submitting comments to this blog post or sending an email to LWW:

infolww7629@livingwatersfortheworld.org

Water Testing Requirements

One of the requirements during the Survey Trip of the Development Phase of an LWW mission project is to sample the source of the water.  LWW recommends that the source water be tested for Hardness, Total Dissolved Solids (TDS), and Metals.  In order to get consistent results, LWW has partnered with a Test America Laboratory in Savannah, Georgia.  The Test America lab is an EPA certified lab, so it must follow specified protocols for any water testing.  The protocols include:

• Testing samples within specified time limits after taking the sample
• Following specified testing protocols that require a specified volume of water to be tested
• Making sure samples are maintained at a certain temperature (4 deg C) and adding preservatives to ensure the integrity of the sample
• Completing a Chain of Custody (C of C) to identify the samples and tests to be run

Because LWW does not require that water testing results be EPA certified, LWW waives the requirements for some hold times, sample temperature, and sample preservatives.

LWW cannot waive the testing protocols or requirements for a properly completed Chain of Custody.

For this reason, each water source must have two (2) full bottles (250 ml each) of sampled water.  If three sources of water are to be tested, then six (6) 250 ml bottles will be required.  All bottles must be labeled with sample source, date, and time the sample was taken.  Label the bottles 1 of 2, 2 of 2, etc so that the lab can differentiate samples.  All sample bottles must be labeled and identified on the Chain of Custody.  See Section 5 in the Field Test Kit Manual for more information and examples.

Importance of Security for LWW Systems

(The following article was contributed by George Strain.)

A team from University Presbyterian Church in Baton Rouge, LA recently installed a system in Havana, Cuba at the headquarters of the Consejo de Iglesias de Cuba (Cuba Council of Churches, CIC). One of the assets touted by their president was the presence of 24/7 guards on the security-fenced premises. After completing our installation and holding our water celebration, the team members and several Cuban ministers went out to dinner for further celebration, leaving at 7 pm. Upon return at about 10:30 some team members checked the installation, only to discover that someone had tried to either operate it, play with it, or who knows what? All valves were in the open position except for the untreated water inlet valve. The pump and ozone system were both on (a single switch controlled power to both, but the pump also required flipping a separate power switch.) Posters explaining the proper uses for clean water had been stood up in front of the system as if to cover the evidence. The pump had run dry, although it turned out to not be damaged. The ozonator had overheated because, in the absence of flowing water, there was no venturi effect to provide suction of the ozone into the water stream. The buildup of heat or ozone damaged all four tubes and melted some insulation from the small diameter pigtail wires from each tube. The bulbs gave off a yellowish light instead of the expected blue. Prozone engineers later suggested that this was probably only the light from the internal bulb and not some residual ozone production capacity. As far as we could tell there was no damage to the ballasts in the ozonator. Understandably, this proved to be a very disheartening end to our week in Havana.

We had included with our system components the LWW ozone spare parts kit, which it turns out only includes one spare tube – reasonable in light of the anticipated operational life of the tubes. We removed one of the four bad tubes and inserted the single spare tube, and became operational again. The downside is that with only one operational tube instead of four, the second pass of water treatment needs to be run four times as long to reach near equivalent ozone levels in the water in preparation for dispensing. This was not the optimal solution.

One of our team members had planned to stay an additional week, and was able to locate spare tubes at the two installations in Cardenas: two at El Fuerte and one at Juan G Hall. These churches graciously allowed us to borrow them. He installed these three, bringing the CIC installation up to the regulation four functioning tubes in the ozonator. The one with the newest manufacturing date gave off the strongest blue light; the other two that were manufactured earlier gave off a weaker light, but are assumed to be functional. Prozone engineers tell us that this is just an artifact of manufacturing when an external coating is placed on the tube. In the meantime, we were able to order four replacement tubes directly from Prozone at the LWW discounted rate ($90/tube) and will be sending them to Cuba in late October with another group.

We don’t know the identity of the culprit in this affair, but have our suspicions. The take-home message from our imbroglio is that none of us can be lax in making certain that the systems we install are truly safe and secure. Because the CIC location has already served as a demonstration model to representatives of all of the denominations that are members of CIC, we risked the reputation of the Living Waters for the World program in the community and throughout the country. The final outcome of our trip was one more clean water system in Cuba, but one that was a bit more expensive than anticipated. We encourage all in-country network teams to maintain a supply of at least four spare ozone tubes and two spare ozonator ballasts (@ $60) in order to quickly return systems to operational status in the event of any damage.

Another Safeguard for the Ozonator – Revised

Bloggers Note: This article was originally posted several years ago, but pulled from the blog when it was learned that the plastic valves recommended do not hold up well in the ozone/air environment. Since that time, LWW has found a better valve that will stand up better in ozone service. Please read on.

One of the biggest dangers for the Living Waters for the World Standard Clean Water System with ozone disinfection, is having water flow backwards from the venturi, through the ozonator tubing, and into the ozonator itself. Since the ozonator bulbs are not water proof, water migrating into them will short out the tubes making them ineffective for disinfection purposes.

There are currently two check valves in the system to prevent water from going in this direction. The first is a rubber, disk check valve inside the venturi body itself. The second is the Kynar check valve that is in the ozonator tubing. When these check valves are operating properly they allow air to flow one way through the ozone lamps and into the venturi. See the pictures below for details.

The other safeguard for the ozonator is to drain the venturi section of piping between each batch while the system is shut down. In the past, we have observed that water left in the system between batches can expand putting pressure on the check valve in the venturi. This pressure was thought to cause premature failure of the venturi check valve.

In some cases, LWW has recommended that system operators disconnect the ozone tubing at the venturi between batches. With a physical disconnect in the tubing, there is no chance of water migrating back to the ozonator. The biggest risk is that the operator must remember to re-attach the ozonator tubing when they start the next batch.

With this blog entry, LWW introduces another safeguard for the ozonator bulbs. LWW suggests that teams could install a manual valve in the ozonator tubing to provide a positive shutoff for the water flow. The preferred valve is PVC with Viton seals and seats that are resistant to ozone. Each connection to the valve is ¼ inch, so it would have to be connected into the ¼ inch tubing adjacent to the venturi. The valve shown below is manufactured by SMC and available from several vendors. The specs are at: http://www.zoro.com/i/G0296676/?category=5796

For his Cuba installations, Jerry Goode glued the valve to a plastic base and secured the valve base to the board. You can see below that the valve stands out and will be difficult to miss.

The valve can be mounted with 1 inch padded clamps and is readily visible. The operating procedures will need to be updated to include turning this valve on and off.

The New Norgas Water Meter

If you are ordering your Living Waters for the World system from FCI, you will probably notice the new Norgas “MultiMag” water meters. These meters look and feel like those in the past, but now have an electrical wire connected to them. This is the latest innovation that allows these meters to be connected to a remote monitoring device. Here is the pitch from the Norgas web site:
“The MultiMag series water meters utilize multi-jet principles for accurate water measurement and are known for their simplicity, longevity, and accuracy. The pulse output capability allows for the MultiMag to be used for remote reading.”
Because Living Waters for the World systems are not ready for remote monitoring, IPs and OPs can simply cut this wire and there will be no impact to the accuracy or operation of the meter.

Other than this wire, connection and operation of the meter is no different than the old meters.
Who knows, maybe this will be the first step for LWW to obtain a water meter with remote monitoring that will enable IPs to monitor the status of their OP systems in “real time.” Just think how that might improve the long-term sustainability of our systems!
Submitted by Ralph Young

One Pressure Gauge versus three Pressure Gauges in the Standard Clean Water System

The earliest Living Waters for the World (LWW) clean water systems were configured to install three (3) pressure gauges around the Big Blue filters. With three gauges, Operating Partners could measure the pressure change/drop across each of the filters and determine when to change the filter. The early criteria for changing the filters specified that when the pressure drop changed an incremental 10 psi from the initial pressure drop reading, it was time to change the filter. PG-1 is the pressure gauge on the inlet side to the 5.0 micron filter, PG-2 is between the filters, and PG-3 is on the outlet of the 0.5 micron filter. If the start-up conditions were recorded in the chart below, then the data recorded six months later would indicate that the 5.0 micron filter should be changed.

After several years of operating experience, however, it was noted that most of our Operating Partners were not tracking this data and had no basis for changing the filters. When the flow rate decreased to an intolerable level, they concluded that it was time to change the filters. In an effort to make the process more sustainable, the LWW Technical Team decided to change the configuration to just one pressure gauge. The criteria for changing a filter would be an iterative, trial and error process. In this case PG-1, is the only pressure gauge installed.

The criteria for the single pressure gauge configuration was that the change must bring the system back to close to its original pressure reading or both filters should be changed.
Following this protocol has its own challenges in that we found ourselves changing both filters when only the 0.5 micron filter needed to be changed.
The LWW Dilemma
As LWW is in the process of updating the clean water systems handbook, how should the three (3) pressure gauges versus the one (1) pressure gauge configuration be considered?

1. Which pressure gauge configuration results in the most sustainable system for our Operating Partners? 3 gauges or 1 gauge

2. Should LWW technical specifications dictate a specific configuration or should that be left to the Initiating Partners to decide with their Operating Partners?

3. What other aspects should be included in this discussion? Your comments are most welcome.

Retrofit of LWW System #17 in Guatemala

I recently received a call from Miriam Mazariegos, one of the In-Country Coordinators (ICCs) in Guatemala about one of our earliest LWW systems at the Presbyterian Church in Chajabal.  This system was installed in 2004 and is still running.  When Miriam arrived on the scene, she immediately went to work upgrading the system to the current one pump, two-pass standard system with ozone disinfection.

A picture of the retrofitted system is shown below.  This was originally a two tank, two pump system.  The PZ2-2 Ozonator (2 lamp cartridges and a compressor) is still in service with only one bulb being replaced since startup nine years ago.

I’m not sure if you can see it, but the venturi is installed on the water line where the flow is down as opposed to up and against gravity.  The venturi is oriented properly with the tubing connections pointing down in the direction of the water flow.  Miriam reports that she gets good suction at the venturi, but that when the system is down, water flows out the nipple connections.  She has instructed the local team to remove the ozonator tubing whenever the system is shut down to avoid getting water into the ozonator lamp cartridges.

As you study this system, please leave a comment with your observations and suggestions as to how this retrofit might be improved.

Miriam reports that there are many early systems in Guatemala that need similar TLC to get them up and running.  If there are any Initiating Partners out there that would like to take on a retrofit project as a Sustaining Partner, please let me know.

As you consider sustainability, think about this system installed nine years ago and it’s still running today!

Contributed by Miriam Mazariegos and Ralph Young

Hard Wiring the Reverse Osmosis System

Contributed by Tom Pierson

On several follow-up trips to my church’s sites in the Yucatan, I kept noticing that the hot terminal on the RO receptacle was burnt and causing a poor connection, necessitating replacement.  The older higher pressure membrane RO’s (160 PSI) draw over 18 amps @ 120 volts running and surge to three to four times this when starting.  This switched receptacle is rated at 15 amps.  During start-up arching occurs on the hot terminal, and over time will create a poor connection and reduce RO performance.  See photo below.

One solution is to replace this male/female connection with a twist lock male plug and matching receptacle.  The example below is a male 20 amp (220 volt) plug, commonly used on small emergency generators and available at home centers for about $30.

Another solution is to replace the existing plug and receptacle with a hard-wire  30-50 amp HVAC non-fused service disconnect box.  You can find an example by looking on the outside wall of your house near your air conditioning compressor.  This will give you the ability to quickly disconnect the RO for service and provide you good screw type connections between the Romex feed wire and the flexible service cord going to the unit.  There are several styles of disconnect boxes, including the pull type, shown below, the old style side lever and one that appears to have a double breaker, which is actually just an on/off double pole switch.  The pull type costs $10-$12.

Service disconnect boxes are easy to wire for either a 110 volt or 220 volt RO.  Make sure you make the flexible cord is long enough so the RO can be moved away from the wall for easy service access, once the unions are disconnected.  The flexible cord could also be attached to the box with a special type strain connector, instead of a Romex clamp, to avoid accidentally pulling the wires loose.  A simple trick is to also make your ground wire length shorter than the hot and neutral wires, to take the initial strain of accidental pull.

The 110 volt box is shown below.

The 220 volt box is shown below.

Pre-Wired Yucatan Ready Disconnect Box

Reverse Osmosis Membrane Washing

LWW recently got a question from one of our Reverse Osmosis and Softening (ROS) systems operators in the Yucatan. They asked the following:

The ROS system was installed in July 2012. The system operator was concerned about the membranes because the TDS was measuring ~50 ppm even after a softener regeneration. What does LWW recommend?

My short answer to the question was that the RO has probably lost some capacity in the last 8 months of operation. It doesn’t sound like it’s time to wash the membrane, but it is time to take notice and start or continue to take data on system operation. I said that they should plan on washing the membrane after a year of operation. This would be the washing process done by a trained person such as Carlos McGregor with acid and base solutions, overnight soaking, etc.

On the RO system, the regeneration of the resin in the softener protects the RO from Calcium and Magnesium contamination in the water. Calcium and Magnesium are the elements that show up as hardness in the water. These contaminates can foul a membrane very quickly and you can’t wash them out. For that reason, you need to measure the hardness of the water as well as the TDS after the regeneration. With a TDS of 50 ppm you could estimate the hardness at 20 – 30 ppm. I would say that 50 ppm of TDS in the product water is OK as long as you can’t taste any salt in the water.

As an experiment, try measuring the TDS in the waste water as well as the TDS going into the RO. You may be able to run a rough balance of TDS (in) = TDS (out). You could also calculate the %TDS removed and going down the drain in the waste stream. As long as the RO is removing 90% plus of the TDS, then the membrane is doing its job. (This assumes that you are keeping the waste flow about equal to product flow.)

The best way to determine when it is time to wash the membrane is to track the gallons per minute (gpm) output of the RO. If when you start out, the RO product water flow is 3.0 gpm, that is your baseline. The manufacturer says that when the product water flow drops by 10% to 2.7 gpm, then it is time to wash the membrane. The problem is that the drop in flow is very slow, so unless you are writing down data every week or more, the operator will lose track of how the system is performing.

Joanie Lukins added to this advice by reminding ROS system operators that it is recommended that water softeners should get an extra regeneration about every month. This extra regeneration uses more salt, but ensures that the resin is returned to full softening capacity extending the life of the membranes.

If there are other comments on this posting, please submit them.

Thanks, Ralph Young, Technical Director, Living Waters for the World

Adapting to Plumbing not Compatible with Schedule 40 PVC

When working in other countries it is not uncommon to encounter pipe that is not the same specification as the Schedule 40 PVC pipe used to construct the LWW water treatment system.  Normally the entire system will be built using Schedule 40 PVC pipe and connectors.  Sometimes the pipe used in-country may not match the diameter of the connectors entering and exiting the system to and from the tanks and the drain.  This is due to the fact that the outside diameters may be metric or otherwise different than U.S. Schedule 40 PVC, especially if it is not manufactured or sold in the U.S.  If you are not absolutely certain that the pipe you will encounter upon arrival to install is compatible with the system connections, you should insure that you have adapter hardware which will accommodate the differences.  The photo below shows the difference between “thin wall PVC” and Schedule 40 PVC.

For the purposes of this discussion we will assume the use of plastic or PVC pipe to do the pre-installation plumbing of the tanks to and from the system board location.

The simplest solution is to use a flex coupling.  This is normally a black rubber coupling with stainless steel clamps on both ends.  These are usually available for most common U.S. PVC pipe diameters (American Valve makes one for 1 inch Schedule 40 PVC).  Being made of flexible material, they can accommodate slight variations in the diameter of the pipes being connected.  Be sure to take extras for future maintenance as these may be affected by ozone over time.  Also insure that the pipe on each side of the coupling is anchored to prevent pressure from forcing the pipe out of either end.  There are many variations of these couplings and not all are recommended for potable water or pressurized environments.  Most of the potable water issues are based on taste considerations or because the manufacturer did not want to certify it for potable water.  It is felt that most of these couplings are suitable for this application.

Many countries utilize the U.S. NPT threading standard and commonly thread plastic pipes rather than gluing them.  Also, some pipe used in other countries is not PVC and the glue we use is not recommended for other materials.  If there is a possibility of having a 1 inch threaded connection on the pipes being presented at the system board, a variety of threaded, 1 inch Schedule 80 adapters (and other fittings) will accomplish the connection.  Schedule 80 threaded adapters are recommended as the walls are thicker providing extra strength when threaded.  These adapters come in a variety of connection combinations:  Slip, MPT (Male Pipe Thread) and FTP (Female Pipe Thread).  Carry several of each combination:

MPT/Slip       FPT/Slip       MPT/MPT (Nipple)       FPT/FPT          MPT/FTP

The same connection combinations are available in elbows and unions.  Combinations of these fittings should allow connection to pipes with male or female threads.

Ideally, you will determine and/or purchase the in-country tank-to-system pipe and tanks on the planning visit and can have a sample to bring back and use to pack the appropriate adapter hardware.  Only rely on this if you have actually purchased the materials or can be guaranteed that those exact materials will be available when the pre-installation work is actually done.

As a last resort, remember that PVC (and other plastic pipe) can be heated and swedged to a larger inside diameter to accommodate another sized pipe (similar to the swedged ends on some Schedule 40 PVC pipes).  The pipe with the larger INSIDE diameter (or thicker wall) will be heated while the other pipe can be “sharpened’ and used to swedge the opening of the heated pipe.  Take care not to overheat the pipe.  Swedge the opening for at least one and on-half inch in order to insure a sufficient gluing surface.

Last, but not least, remember that ONLY one inch pipe can be used for the tank-to-system plumbing.  Any smaller diameter can adversely affect the flow rate and impede the efficiency of the venturi.

Contributed by Jerry Goode, Co-moderator of the Cuba Network