One NO-DES unit (truck or trailer) can flush on average one mile of mains per day!
One NO-DES flushing unit (truck or trailer) can efficiently 100% flush the average city with a population of approx 40,000 to 60,000. Understand that most water departments would not conventionally hydrant flush (to waste) their entire distribution system in one year; they would divide it up into third’s, forth’s or fifth’s (taking 3, 4 or 5 years to complete 100% of their water distribution system). With the NO-DES flushing technology they could flush their entire proposed system (based on a population of 50,000) each year; that’s 100% of their distribution system each year using the NO-DES flushing technology!
There are approx 1,250 fire hydrants per every 50,000 in population (a conservative estimate). For our case study we use a city population size of 50,000 with approx 1,250 fire hydrants. The conventional hydrant flushing crew would consist of two or three persons (having to comply with NPDES regulations, etc) – The NO-DES flushing crew would also consist of the same two or three persons! So labor is the same!
Each hydrant can flow between 500 and 1,500 gpm from the hydrant steamer ports (4” or 4-1/2” Port) all depending on main sizing and system pressures. So for a conservative estimate we will use 1,000 gallons per minute for the flow rate. The average time flushing at each hydrant is 15 minutes. 1,000 gpm times 15 minutes equals 15,000 gallons lost from each hydrant flushed, on average.
Using the NO-DES flushing technology scenario they could flush the entire distribution system (with a population of 50,000) which would equal 1250 hydrants that would have been flushed to waste using the conventional hydrant flushing method (but was now conserved using the NO-DES technology) – So to calculate the water saved (after NO-DES flushing for one year) you would take 1,250 hydrants x 15 min’s x 1,000 gpm = 18,750,000 gallons of precious water saved (that’s 18.75 Million Gallons saved) in just one year. The average cost of the water lost is $3,000 per million gallons – so $3,000 x 18.75 mg = $56,250 saved each year. At this rate the NO-DES equipment would pay for itself in approx 5 years.
If your population is 100,000 and you had one NO-DES unit, you would flush 50% of your distribution system each year (for two years) and it would still pay for itself in approx 5 years.
After reading the above case study how could any water manager opt to use wasteful conventional hydrant flushing methods ever again? Just ask yourself; how much water and monies did you save using your wasteful conventional hydrant flushing methods last year! Yes, it’s that easy! The crew trucks, the back-hoes and the vac trucks that you purchased are more expensive than our NO-DES units, and they will never give you a return on the investment!
Remember NO-DES flushing technology helps save our environment from chemicals, and:
•It saves approx 6% (or more) of all water supplies annually!
•It saves the energy required to produce, treat, pressurize and deliver the water.
•It improves the water quality to a higher standard than it was before delivered.
•It cleans and scours the insides of the mains more effectively than conventional flushing techniques!
•It eliminates NPDES issues and fines!
•It increases the safety of the water by increasing the disinfection “in the distribution system”.
•It solves issues with chloramines, removes bio-films, reduces HPC levels and eliminates nitrification issues.
•It refreshes the water – eliminating water age at dead ends!
•It helps to reduce DBP’s.
•It reduces water quality complaints from the CUSTOMER!
•It eliminates pressure loss and surging (water hammer), reducing main breaks and main damages.
•It eliminates property damage.
•It improves PR with customers! Cities can lead by example in water conservation!
•NO-DES flushing technology saves money – It pays for itself!
Any argument against saving water, saving money or improving water quality is only hurting your customers!
This is so simple:
Conventional Flushing Wastes the Water – The water and monies are lost forever!
NO-DES Flushing Saves the Water – So it pays for itself; you own it and control it!
Below is an example of how NO-DES can flush large additional loops from one set-up location:
First flush (bright yellow) – Set up between H1 & H2 on Donald, approx 800’ directly between hydrants.
Second flush (purple) – Same set up location between H1 & H2 on Donald – but flushing approx 2,400’ on Calle Del Prado & Via Verde & Donald – Close valves #1, #2, #4, #19 & #17
Third flush (red) – Same set up location between H1 & H2 on Donald – but flushing approx 2,800’ on Calle Del Prado & Via Verde & Donald – Open valves #19 – Close valves #17 & #18 – Leave valves #1, #2, #4 & #17 Closed. Note: Only the red section of this flush is counted as newly flushed main!
Forth flush (Green) – Same set up location between H1 & H2 on Donald – but flushing approx 2,600’ on Martin & Via Verde & Donald – Open valves #2 & #17 – Close valves #3, #8, #15 & #20 – Leave valves #1, #4 & #18 Closed. Note: Only the green section of this flush is counted as newly flushed main!
Forth flush (dark yellow) – Same set up location between H1 & H2 on Donald – but flushing approx 1,600’ on Camino Del Valle & Martin – Open valves #3 & #8 – Close valves #7, #11, #16 & #17 – Leave valves #1, #4, #15, #18 & #20 Closed. Only the dark yellow section of this flush is counted as newly flushed main!
Fifth flush (blue) – Same set up location between H1 & H2 on Donald – but flushing approx 1,600’ on Las Vegas Dr & Ashley & Calle Corta – Open Valve #11 & #16 – Close valves #25 – Leave valves #1, #4, #7, #15, #17, #18 & #20 Closed. Only the blue section of this flush is counted as newly flushed main!
Sixth flush (Orange) – Same set up location between H1 & H2 on Donald – but flushing approx 1,000’ on Ashley & Via Corta – Open Valve #7 & #11 – Close valves #10 & #16 – Leave valves #1, #4, #15, #17, #18, #20 & #25 Closed. Only the orange section of this flush is counted as newly flushed main!
Seventh flush (pink) – Same set up location between H1 & H2 on Donald – but flushing approx 2,300’ on Van Ct & Las Vegas – Open Valve #10, & #15 – Close valves #7 & #12 – Leave valves #1, #4, #16, #17, #18, #20 & #25 Closed. Only the pink section of this flush is counted as newly flushed main!
Eighth flush (light blue) – Same set up location between H1 & H2 on Donald – but flushing approx 300’ on Via Corta – Open Valve #12 – Close valves #10 – Leave valves #1, #4, #7, #16, #17, #18, #20 & #25 Closed. Only the light blue section of this flush is counted as newly flushed main!
Ninth flush (light blue) up on Clinton – Same set up location between H1 & H2 on Donald – but flushing approx 3,200’ on Clinton & Alameda & Camino Del Valle – Open Valves #4, #7, #10, #16, & #25 – Close valves #2, #13 & #21 – Leave valves #1, #17, #18 & #20 Closed. Only the light blue section of this flush is counted as newly flushed main!
Tenth flush (dark blue) up on Rufffin Av – Same set up location between H1 & H2 on Donald – but flushing approx 3,200’ on Ruffin & Alameda & Camino Del Valle – Open Valves #21 – Close valves #24 – Leave valves #1, #2, #13, #17, #18 & #20 Closed. Only the dark blue section of this flush is counted as newly flushed main!
Total of 21,800 feet of main NO-DES flushed from one location (set up)! = 4.13 miles of main NO-DES Flushed (one set up, one day)
In the bay area we have found that the NO-DES flushing system cost approx 50% less than uni-directional flushing. The NO-DES system will pay for itself over time – Uni-directional flushing will always waste water and money (it will never pay for itself)!
The water saved can be construed as a new water source for planning purposes!
Size of mains to be flushed –
Most mains above 12” are considered transmission mains and normally maintain a flow significant enough to prevent particulates from settling.
Both uni-directional flushing and NO-DES flushing utilize hydrant ports (4” or 4-1/2” steamers, or 2-1/2”) to flush. When uni-directional flushing you are dependent on the distribution pressure to force the water out of the hydrant; if you have an average pressure of 70 psi and are using the 4-1/2” port, you can only achieve approx 1,500 gpm (plus or minus 300 gpm) of flow. To achieve a 5 ft/sec velocity inside the target main, the 1,500 gpm limits you to a maximum of a 10” main (or a 12” main at 3 ft/sec)!
If someone is conventionally flushing a 20” main from a hydrant port, they can’t even achieve one ft/sec flow velocity inside the pipe. In reality they would only be dumping the water, not flushing/scouring the main. And if they needed to just dump the water, they could now use the NO-DES system to clean the water (filter and clean it), for any size main!
Because the NO-DES system utilizes a pump to circulate the water, we can achieve the flows required to flush a 12” main with our demo unit – and up to an 18” main with our new single vessel models.
Cleaning the inside of the main –
Most city crews don’t measure the flows from the hydrants when conducting Uni-direction flushing; it’s just a guess that the flow is significant enough to clean the inside walls of the main.
NO-DES has a flow meter in the control panel that allows the operator to achieve the exact flow required to accomplish the flush at the desired velocity (inside the main). We also use the patented “Reverse Flow Process” that directs the flush in the opposite direction of the normal distribution flow; creating better scouring/scrubbing of the inside walls of the main.
Turbidity and Water Quality –
Most city crews use a glass jar to visually inspect the flushed water, to determine the water quality and if enough flushing was performed. Because the water is being pulled from other areas of the distribution system, there are always some remaining particulates in the water (always)…
NO-DES utilizes two turbidity meters to analyze the water to exact standards, which determines when the flushing process is complete! Because the NO-DES process only flushes the section of main that’s located between the connected hydrants; the finished water quality is always perfect (below 1 NTU), and no other parts of the distribution system are effected in any way! This equates to “NO COMPLAINTS”…
Water Loss – Water Saved –
There’s no comparison with NO-DES when it comes to saving water! Conventional flushing wastes untold millions upon millions of gallons of water each year – NO-DES only spills the amounts left in the hose after shutdown (a couple hundred gallons)!
When conventional flushing to waste, city crews have to comply with NPDES regulations (de-chlorinating, sand bags, storm drain filters, etc). And for some reason the ammonia remaining in the water is allowed to pollute our rivers and lakes!
Because NO-DES spills less than 1,000 gallons each flush; no NPDES issues are required.
Water Hammer and other Hydraulic damages –
During conventional flushing, the opening and closing of the hydrants cause lots of damage to the distribution system from water hammer. Another aspect of hydraulic damage is created when the crews open the hydrant full open when flushing smaller mains.
When operating dry barrel hydrants, if the hydrant is not opened to the full open position, the drain hole at the bottom of the bury will allow high pressure water to discharge and will cause damage to the environment around the hydrant installation.
If the main to be flushed has a cement lining and the velocity exceeds 5 ft/sec, the lining could be damaged.
Because NO-DES utilizes hydrant control valves, there is never a serge or hammer to the distribution system. The NO-DES variable speed pump does not cause any pressures surges to the distribution system (any time). And again the flow meter allows the operator to flush at exactly 3 or 5 ft/sec as desired.
Production per day –
The amount of main flushed per day can vary for both types of flushing methods. We have experienced the same results/amounts on most occasions, so it would be fair to call them equal for current measurement purposes.
Sensitive Areas (Damages) –
Conventional flushing can damage property. NO-DES does not.
Low Pressure Issues –
Conventional flushing cause’s low pressure issues when the hydrant is opened. NO-DES has no effect on the distribution pressures or flows.
Conventional/uni-directional flushing requires lots of valving (lots of broken valves), and the possibility of leaving valves closed.
NO-DES flushing requires almost no valving at all – Sometimes to create a larger loop to flush, it becomes necessary to close one; but they are not required to close them off completely (or tightly), the valves only need to be taken down to the bottom to where it just touches.
Disinfection Issues –
NO-DES has the capability to inject disinfectant (very small quantities) – Uni-directional flushing methods cannot!
As you know, our NO-DES flushing technology has the ability to filter a small section of the distribution system water (down to 1 micron absolute) and then apply small concentrations of chlorine to boost the residuals. This works very well with our equipment because we are circulating the water thru our (equipment) which becomes an above ground loop of the distribution system itself! We are able to safely achieve mixing and contact time within the distribution system without affecting the customers (I don’t believe anyone has been able to achieve this within distribution systems before). One of our customers was flushing (to waste) large volumes of water because the chlorine component of their chloramine disinfectant would dissipate, leaving free ammonia, which in turn would speed up the nitrification process.
We discovered that we could measure the amounts of existing free ammonia in the area to be flushed (with our NO-DES flushing system) then add just enough chlorine to re-combine with the ammonia to re-form more chloramines – This allowed them to save the water, improve the water quality and re-institute their chloramine residues! Because we also filter the water (again down to 1 micron absolute) thus removing the bio-films that were creating the problems; wham, the wasted water issue, the water quality issue, the residual issue, the nitrification issue and the customer complaint issues are all solved (and all at a lower cost).
Customer Complaints –
Most city’s have a section of their web site dedicated to explaining dirty water complaints for when crews are (conventionally) flushing. When using conventional flushing methods in the past, Hillsborough CA would see 10 to 15 customer complaints per flush – Since implementing their NO-DES flushing system they haven’t received one customer complaint!
P R –
When comparing NO-DES flushing to uni-direction flushing, we believe 100% of your customers will side with conserving water and improving the water quality; this is a no brainer!