Frequently asked questions

The only water main flushing method to improve water quality, eliminate NPDES issues, and conserve water.

Below you will find answers to frequently asked questions. Click on a listed question to jump to the answer. If you have a question not listed on this page, please contact us.

 

 

What does the acronym NO-DES stand for?
(A) Neutral Output Discharge Elimination System.

How does the NO-DES system work?
(A) Instead of water flowing out of fire hydrants and running to waste, the NO-DES process utilizes a trailer mounted pumping, filtering and re-chlorinating system which circulates the water within the water distribution system.  The NO-DES unit is connected with large hoses between two fire hydrants, which creates a temporary "loop" in the water distribution system.  A pump on the unit circulates water at prescribed velocities where it is passed through a series of filters which remove intentionally "stirred up" sediment and particulate matter.  Disinfectant can be added to further improve water quality and ensure its safety, something current methods cannot achieve. Inline turbidity meters indicates when desired clarity levels are met, taking the guess work out of knowing when the flushing has achieved its purpose.  The result is improved water quality, increased disinfectant residuals, conservation of two vital natural resources - water and the energy it took to pump and produce it - all at a lower cost without taking the value of the saved water into account! Since very little water is lost with the NO-DES Process, NPDES issues are eliminated.  Additionally, the flushing can be done by a crew of 2-3 operators and typically doesn't require that any sections of the distribution system be valved off. 

What is the pressure rating on the NO-DES equipment?
(A) The standard model Trailer and Truck has a maximum system pressure rating of 150 psig max.  We also offer the Trailer and Truck models with the capability of 300 psig.

How many employees does it take to operate one NO-DES unit?
(A) We suggest three, although it can be operated with two.

What does the NO-DES system remove from the distribution water?
(A) The NO-DES flushing system can remove settled particulates, bio film, iron and manganese and some sources of color.  The NO-DES unit as well as conventional flushing methods may not remove heavily encrusted "barnacle" types of long term rust buildup found inside old cast iron and steel mains.  The fix for these issues may require “pigging” or other extensive, expensive and very intrusive solutions.

What are the turbidity levels entering NO-DES system?
(A) Once the NO-DES system starts circulating the water and stirring up any sediment, the water quality quickly decreases to a brown rusty color with turbidities well over 100 NTU’s. Typically, within two to five minutes water quality returns to accepted distribution system standards. Each water distribution system is different, and conditions could be much better or much worse. For distribution systems that are extremely bad, we recommend that the municipality perform a onetime system wide conventional flush prior to implementing the NO-DES system. If this is not performed, you might experience higher filter loading conditions with the NO-DES system; making the first system wide NO-DES flush more costly with frequent cartridge replacements.

How can the NO-DES system save money?
(A) Savings realized when using the NO-DES system will vary, depending on a variety of factors. These factors include how flushing is currently being performed (conventional or uni-directional), number of operators being used, wholesale water costs and water production and delivery costs. Utilities can reduce these costs by 50% or more. However, the greatest benefit may come in the form of your customer's positive perception of your utility by leading by example in water conservation; and no longer opening fire hydrants and wasting tremendous amounts of water.  This is especially true for those utilities that have voluntary or mandatory rationing requirements in place, which typically include fines for wasting even the smallest amounts of water.

Is the NO-DES system only for purchase or is it a contractual service?
(A) The NO-DES flushing system can be purchased, leased or financed. No-Des also offers Tax Exempt Municipal leases and Tax Exempt operating leases as well, to those that qualify.

Can the NO-DES method achieve typically desired flow rates of 3-5 feet per second in water mains that are 2”-12” in diameter?
(A) Yes, the NO-DES system and unit can meet these AWWA recommended flushing velocities in 2”-12” water mains. With NO-DES, water hammer potentials are eliminated, as the water velocity is being provided by the NO-DES unit’s pump, not the rest of your distribution system. Only the water within the temporary piping loop is being circulated, filtered and disinfected. This greatly minimizes the impact on your distribution system and customers.  If the flushing of water mains larger than 12” is desired, two NO-DES units can be hooked up in parallel.

Can the NO-DES unit produce higher velocities than the AWWA recommended 5 feet per second?
(A) Yes. However, this is something that only the utility can determine is desired, safe and appropriate given their system’s age, type of pipe, etc.

Can the NO-DES system add disinfectants?
(A) Yes, each NO-DES system comes with a chlorinator for injecting very small concentrations of chlorine for boosting residuals.

Will the NO-DES system work in a chloraminated water distribution system?
After working extensively with technical experts, we’ve developed our process in a way that enables the NO-DES flushing unit and system to combat issues by both flushing and boosting chloramine levels.  This is achieved by precisely adding the appropriate amounts of chlorine during the flushing cycle, which then combines with the measured free ammonia in the water to reform chloramines.

Many utilities flush solely to remove water with high free ammonia levels, in an effort to prevent nitrification from occurring. The NO-DES unit can be used solely for that purpose as well, reducing the free ammonia levels by reforming chloramine levels to the desired concentration in large sections of main (much larger than a flushing cycle).   

The significance of using our NO-DES unit is that it can target specific areas where and when chlorine/chloramine boosting is needed – which is a feature unique to our product.  Used in this manner, it functions as a portable re-disinfection boosting system.  Flushing is also performed at the same time, which will significantly slow down the deterioration of the systems disinfectant residual in the future.

Does the NO-DES system and unit use components that are approved for use in public water distribution systems?
(A) Yes, every component that comes in contact with distribution system water is approved for use in potable drinking water systems.

What is the maximum distance the NO-DES system can flush (hydrant to hydrant) or (hydrant to blow-off)?
(A) The NO-DES system comes with 1,000 feet of 5” hose, and over 400 feet of 2-1/2” hose. You can order additional hose, but after 1,000 feet the rate of flow will start to diminish to a point of being ineffective on some sized water mains.

What kind of trailer is the NO-DES equipment mounted on?
(A) The trailer is a common gooseneck design, 20 ft metal deck with two axles (double tandems) that can be towed with a standard pick-up style truck that has a tow rating of approximately 20,000 lbs or more (example; Ford F450 and F550 or Dodge 4500 and 5500). The maximum gross weight rating of the trailer is 24,000 lbs The NO-DES trailer system only weighs approximately 15,000 lbs (dry) and just over 16,000 lbs (wet). The trailer has electrically actuated brakes on both axles.    The gooseneck set-up allows for a reversible ball system to be mounted in the bed of your truck; so when you’re not towing the gooseneck trailer you just flip the ball over and the receiver is now perfectly flat with the floor of the truck bed.  NO-DES uses a Ford F450 truck with a combined vehicle towing capacity of 29,000 lbs to transport its demonstration unit. The gooseneck trailer design can turn under the gooseneck at up to 110 degrees, allowing you to maneuver the truck and trailer combination into tight places with ease.

The NO-DES flushing system now also offers the option of a truck mounted unit. The truck is rated just under 26,000 lbs and does not require employees to obtain a commercial drivers license. Please contact us for more details. 

What kind of filters are used with the NO-DES system?
(A) The NO-DES system has two separate stainless steel filter housings by Fil-Trek. Both are ASME "U" stamped and compliant. A. The first filter housing is designed as a roughing filter utilizing 12 “disposable” filter bags that remove particulates down to 5 microns in size.  Though the run times on these filters are dependent on the amount of particulate matter, bio-film, etc in the distribution system being flushed, we estimate typical run times will be in the 1-3 week range. Again, depending on the condition of your distribution system, run times could be longer or shorter. Recommended change out differential head pressure is 20 psig.  (B). The second filter housing is designed as a polishing filter utilizing an additional 12 “disposable” filter cartridges, capable of filtering out particulates down to 1.0 micron absolute.  We estimate run times for these filters to be in the 3-6 week range, again depending on the conditions as noted above. The filter vessels have a flow capability in excess of 2000 gpm. 

What type of pumping unit is employed on the NO-DES system?
(A) The pumping unit on the trailer is comprised of a small tier IV emissions 38 HP three cylinder (air cooled) Hatz diesel 3L41C “Silent Pack” design with a noise dampening enclosure, and a residential silencing muffler. The power package includes a Techno drive Power Tak-Off, Murphy Shutdown panel, and 12 volt battery with cables. The entire package is mounted on a base plate which contains a30 gallon fuel tank and battery. The pump and driver are connected through a flexible, electrometric coupling, and covered in an OSHA guard. The 2K6x4-13" Durco Process pump unit can operate at approximately 1,000 gpm to 1,400 gpm (based on the size of main, distance between hydrants/blow-offs and filter loadings).  This equates to being able to flush a maximum of 12" mains at 3 ft/sec velocity, and 10" mains at the desired 5 ft/sec velocity.

Does the NO-DES unit come with hydrant hoses?
(A) Yes. Included with the NO-DES unit is over 900 feet of 5 inch collapsible, approved water transfer hose and fittings, with most of the hose in 100 feet lengths. Also included is over 400 feet of 2-1/2 inch hose for flushing smaller mains, water meter testing and other tasks that do not require the larger hose.

How are the 5” hoses rolled and un-rolled?
(A) The hoses are rolled and unrolled by using specially-designed hydraulically operated hose reels, which minimizes the physical labor required and saves time.

How are the reels powered?
(A) The hose reels are attached to and powered by a small forklift that piggy backs onto the back of the trailer and is included with the NO-DES unit. The forklift is a Burro model from the Quality Corporation in Denver, Colorado. The forklift can lift 3,000 lbs. and is powered by a 13 HP Honda gasoline engine. The hydraulic system of the forklift also powers the reels. Top speed for the Burro is 3 mph and is a walk-behind model that comes equipped with an orange emergency strobe plus forward and back facing lighting for night operations.

How can traffic cross over hoses laid across an intersection?
(A) Included with the NO-DES unit are two sets of hose ramps that allow traffic to pass over the hose under such circumstances.

Does the NO-DES unit measure flow?
(A) Yes. The NO-DES unit has a built-in flow meter with a remote read display that enables you to attain exact flow information, and a totalizer for tracking use.

How does the NO-DES system help determine when the flushing is complete?
(A) Turbidity meters are located at the pump inlet and at the outlet of the polishing filter to determine water clarity (start to finish).

Can the NO-DES system replace or be used as a portable booster or transfer pump?
(A) Yes, and with the increased benefit of being able to filter and disinfect the water being pumped - something traditional booster systems cannot do.

Can the NO-DES system be used to backwash on-site GAC filters?
(A) Yes. GAC backwashing is an additional function the NO-DES unit can perform.  To do so one end of the transfer hose is connected to the backwash drain outlet of the GAC filter and the other to the inlet of the NO-DES unit. A second transfer hose is connected from the discharge of the NO-DES unit to a hydrant located in the distribution system.  The backwash cycle can be controlled by the NO-DES unit without interruption, and the cartridges/bags can be disposed when backwashing is complete.

Can the NO-DES system be used to drain storage tanks for maintenance, recoating, etc?
(A) Yes, to do so one end of the transfer hose is connected to the drain outlet of the tank and the other to the inlet of the NO-DES unit. A separate transfer hose is then connected from the discharge of the NO-DES unit to a hydrant.  Again, the benefits are that the NO-DES unit will filter the water that is being transferred into the distribution system and can also be chlorinated if desired.

Can the NO-DES system be used when performing in-the-field large meter testing?
(A) Yes. Instead of discharging water into the street, a 2-1/2" hose is attached to the discharge side of the test meter, with the other end being connected to the inlet side of the NO-DES unit. This water is then filtered, and disinfected if so desired before being returned back into the distribution system via a hydrant.  The NO-DES unit’s flow meter can be used to confirm the accuracy of the meter being tested.

When the water flows out of the hydrant, into the NO-DES system via the hoses; is the water considered waste because it left the distribution system?
(A) No. Once the NO-DES unit is connected to the hydrants or blow-off's, and is pressurized by opening the hydrants or blow-off's (full open); the NO-DES unit becomes a temporary part of the distribution system, just as a booster pump system does when used to transfer water or boost pressures.  The distribution system water does not leave the distribution system; it is circulated through the connected "temporary loop" created by the NO-DES system.  The water is not pumped anywhere (out or back in), it is only moved in a circle (circulated).

During conventional or uni-directional flushing practices, is the flow from the hydrants measured or controlled?
(A) Most hydrants are of the dry- barrel type; dry-barrel type hydrants must be fully opened while flushing, otherwise the drain hole located at the bottom of the bury (which only seals when the valve is in the full open position) will allow water to escape.  During extended operations, if the hydrant valve is in any other position water will flow out of the drain hole with enough force to erode and undermine the area around the hydrant bury.  As a result, when using conventional or uni-directional flushing methods, operators are likely turning hydrants to the "full open" position and may not be monitoring or controlling the flows to keep them within or reaching desired flows. The NO-DES unit enables you to precisely adjust the rate of flow with our variable speed pump and flow meter.  An attached placard shows the operator exactly what flow rate is needed to achieve the desired 5 ft/sec velocity for each size main to be flushed.  This removes any chance of missing the target velocity, and addresses issues such as water hammer or lining damage.   

Can the NO-DES system be used to test fire flows?
(A) Possibly. This could be accomplished if the water from the hydrant was discharged into a water tanker truck while performing the flow test and then was withdrawn by the NO-DES unit and pumped it back into the distribution system. This has not been tested yet, but the concept is simple and NO-DES will be evaluating this task in the near future, as it provides for another opportunity to conserve water.

Does the NO-DES flushing system stir up sediment and particulate matter in parts of the distribution system outside the “temporary loop that is created when flushing with the NO-DES system?
(A) No, unless the NO-DES system is connected improperly. The NO-DES system was designed to be connected so that the direction of flow inside the main being flushed is in the opposite direction of flow of the distribution system. As an example, if the general distribution flow is 30 gpm traveling through a 6” main being flushed, the NO-DES unit will circulate the water to its desired flow rate of 441 gpm in the opposite direction. The 30 gpm distribution system flow will be circulated through the NO-DES system and then continue on down the water main in its normal flow. See the below illustration.

NO-DES Unit

As the NO-DES system circulates the water between the two hydrants in the opposite direction of the distribution flow, any stirred up sediment will be carried to the inlet of the NO-DES unit (along with the 30 gpm distribution flow). All this water is filtered and then circulated back into the main where the 30 gpm distribution flow will continue down the main under normal flow conditions. 

If the distribution system flow in the above sample was 300 gpm, would the NO-DES system have to produce the 441 gpm plus 300 gpm to achieve the desired opposite velocity inside the target 6” main?
(A) No, if the distribution flow is 300 gpm in that 6” main; there’s no reason to flush that section of main, it’s being flushed all the time

Will NO-DES train our employees on its proper use?
(A) Yes. Training in the use of the NO-DES unit is included in the purchase price, as is the delivery of the unit. At the completion of the training employees will receive a certificate of training on the forklift, as required by OSHA, as well as a certificate of completion for training on the NO-DES unit. Arrangements can be made to have NO-DES train other employees as the need arises.

Once ordered, how long does it take NO-DES to deliver a unit?
(A) Based on current component part delivery times we estimate delivery to be made approximately 120 days after receiving an authorized Purchase Order. Our goal is to shorten that whenever possible.

Will the NO-DES system remove bio film?
(A) YES - Bio-film has been a big problem with almost all water systems, and up to now the only way to remove bio-film was to conduct extensive flushing to waste! With the NO-DES system you can not only remove this issue, but you can stay on top of bio-film build-up through a dedicated year round program using the NO-DES system. Because there is very little water wasted, the NO-DES system can be employed 24/7, 365 with no adverse effects towards your distribution system or customers.

Can the NO-DES system be used for flushing after water main repairs?
(A) YES - This issue is a big concern with water providers, not only have you just seen large amounts of good treated drinking water spill down the gutters during a water main break, but once repairs are complete, your crews are now going to flush the area to waste to ensure that the water is safe and clean. If you owned a NO-DES unit, you could flush the area of concern and add disinfectant without wasting more water, something that has never been performed before, but always desired. Now by using the NO-DES system, not only is the water clean and safe, it's also ready for Bac-T sampling.