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“Man Your Stations” Your Waste Water Pump Station That Is.

Sound familiar?

The famous saying is related to a call to General Quarters and that all sailors drop what they’re doing and report to their battle stations.  A far different scenario than those good people employed to man and run a waste water pump station but there is a link between the two environments- although granted the military call to duty is much more critical in nature let us play a bit with the words of “manning” ones station as it applies to the waste water sewer pump station.

A Waste Water Pump Station is dependent upon the men and women who oversee the daily operation of the station!

The most important aspect of any station is the condition of the equipment.  The men and woman of the military are trained constantly in the importance of maintaining their equipment, whether it be a riffle or their personal safety equipment, with very good reasons as to why.   Likewise the equipment in a waste water pump station is dependent upon good diligent people who understand the importance of inspection checks and the ensuing upkeep of the equipment.                                                                                                  So we will not go into detail of how to maintain the station, but how to hire so that the station is “manned “properly.  As the person responsible for hiring the sewer pump station technician insure you have a well defined scope of duties beforehand and any waste water or DEQ (Department of Environmental Quality) certifications, applicable to the position to be filled.  Once the applicants certifications are met insure the  distance from prospective employees home to the work station is not so far to prevent the worker from arriving quickly in case of an emergency.  For it is critical that you man the waste water station as soon as possible following a high level alarm!  A sanitation worker showing up a couple of hours after a sanitary sewer overflow has occurred  is practically relevant to “Dereliction of Duty” and outside the limits of the requirement “the pump station technician must be able to respond in a timely manner …”.

So, you believe you have found a “few good men” (women) with the experience to handle the day to day operation of that 4 MGD Sanitary Pump Station adjacent to the the Willamette River.  Here is what to look for in a waste water station operator. 

  1. Someone you feel is not an individual employee but will embrace a team member concept and that everyone is a safety captain. Re: Safety, most pump technician can quote OSHA’S 1910 .146.  The competent person duties section in regards to confined space rules & regulations.  Remember a waste water wet well rates the highest in the danger modifier scale as compared to the other confined space environments.
  2. Look for the employee who asks about your system and its components.  Who want to know brand names of equipment and can tell you why an Allen Bradley programmable controller is a good system.  This potential hire has already accessed your municipal infrastructure and its components by looking up articles on the internet that maybe relevant to the waste water pump station that he or she will be supervising.  So the good candidate for employment must show that they are a proactive type of person and will exhibit an erudite behavior beyond that of a regular journeyman.
  3. Here is a little secret on hiring good pump techs for the waste water lift station.  I of course, look first for those with prior waste water pump station experience.  However, if not much previous experience i will look for an automotive repair background, especially those with an ASE (Automotive Service Excellence) certification.   The individual who has a background in reading the logic readouts and diagnosing electronic faults of the new cars easily adapts to the basics of SCADA (supervisory control and data acquisition) and the iPhone, as a remote control unit to access the programmable logic features the waste water pump stations programmable logic control features.  They also have the engineering concepts of a pump.  The “Rotodynamic” automobile water pump works on the same principal as the centrifugal pump that moves the potable water in your water lift station as well as the submersibles, in your waste water station.  If you are a smaller water or sanitation district you will appreciate the mechanical background of the automotive tech in keeping all other equipment running from your service truck to your small trash pumps.
  4. Look for neat and properly dressed applicants.  Those who look like they could walk out into the work environment and operate your waste water pump station  the day of the interview.
  5. Dependability is of greatest importance.  I would have probably listed it at #1 in importance-but realizing most HR managers-have checked on the potential hire employees references as to his or hers punctuality and job attendance at the end of the interview this “If a waste water pump station is in an alarm condition with the potential overflow looming or worse yet a sanitary sewer overflow is in effect and the time is 12:00 AM would you respond quickly and work safely when there “?  If the potential employee responds without hesitation (this is important,no hesitation ) a resounding yes then I don’t have my next employee but I have just signed up a sanitation pump station technician that will be part of a team and properly man the waste water pump station.Lastly, keep your good people once you employ them, and keep reading “See you at the station”
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See you at the Station – Keep it Simple Waste Water Lift Station

“Keep it simple, Sir”, when designing a Packaged Waste Water Lift Station.

No disrespect here as the acronym “KISS” is well known to stand for “Keep it simple stupid”. Sir, is much more appropriate as we are dealing with professional engineers and public works officials who undertake a difficult task when specifying a packaged waste water lift station. As experienced packaged waste water lift station builders, designing an easy to operate waste water lift station is beneficial to both the end user, and the maintenance workers charged with overseeing the stations daily operations.

Packaged waste water lift stations need not be complicated in their design. Specifications are DEQ (Department of Environmental Quality) originated in most cases and because the regulations governing waste water lift stations are generally standardized, with some variance, making it easy for an experienced builder to follow and construct. The licensed engineer will work with the packaged builder of the waste water lift station from the concept to test run-up.

 

This scenario can be reversed if the builder of the waste water station is the generator of the order, either way it is close working relationship. The municipal waste water station is always a custom station but that has more to do with add on equipment and mostly as it applies to electric equipment. An easy to operate waste water lift station may function fine without Variable Frequency Devices (VFD), noting if they are low horsepower pump motors and flows are fairly constant, the basic across the line start, adequate capacity non clog pumps would be appropriate.

Remember in the laws of physics you do not get something for nothing. The VFD has an initial capital cost that must be considered and there is additional cost in energy use (slight as it is) that the VFD requires at BEP or higher flows. This can actually increase energy costs over time.

A waste water lift station is comprised of four basic components.

  • The Pre- Cast Concrete section is where we find the concrete structure consisting of the standard 6’ diameter barrel sections, occasionally lined with High Density Polythylene (HDPE) , and commonly in depths of 20’.
  • The base of the station is also concrete and historically sloped where the sides have a fillet design to keep sludge from settling at the outer circle. This design is changing as of recent to an easier to clean design to save on fuel and labor cost as well as the regulatory costs in conforming to OSHA.
  • Discharge piping and valves are usually housed in a concrete vault and included in the scope of supply “Precast Concrete”   The mechanical equipment includes the pump and motors,in a duplex configuration with the pump of choice being  of a submersible design. Valves and discharge piping, with  pressure gauges to withstand the demands of waste water are and specified in the mechanical package.
  • All submersible pumps need a retrieval system and we include all stainless steel guide rails in the metals section. Hatches and lids, made of stainless steel but sometimes aluminum and are included under specialty metals.

All of these components are complimented by the electrical components. The controls of increasing proficiency are integrated in the manner that they are matched to the motors and in most cases made by the VFD manufacturer when drives are specified. All things done repetitively will usually get easier! General Contractors often comment to me of the need for a “Packaged waste water lift stations”. I always compliment their knowledge but state I believe there is advantage to having a station built by a supplier who is working with the components daily whether shipping a complete station or assisting with a retrofit of a jockey pump in  an existing waste water lift station. When you live and yes sometimes (have to breathe) waste water lift stations you design in simple, but well planned and of superior quality components. SEE YOU NEXT WEEK AT THE PUMP STATION

 

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See You at the Station – NPSH

A Positive Story about Managing the Liquid Limit in a Waste Water Lift Station

 

Here is the good news about understanding the concept of, Net Positive Suction Head or NPSH. If you understand the theory of Bernoulli’s principle you probably do not need a basic overview of NPSH. The bad news is maybe you haven’t the foggiest idea of how this mathematical equation helps one determine the value of NPSH.

 

Photo Credit Wikipedia

Photo Credit Wikipedia

After sometime spent on the internet I believe the best definition of NPSH:

 

“NPSH is used to denote the suction performance of a pump without regards of the system to which it is installed.”

 

Sounds simple enough, but it is not.

 

In all actuality submergence level of a pumps intake in relation to the surface of the water above creates a better picture of what we are attempting to define. Remember that the height of water produces head, or what is called pressure head. The distance of the pumps intake below the surface of the liquid gives us the basic concept of suction head.

 

With the basic understanding of NPSH you can better conceive of what is meant NPSHa or suction head available. As an installer of packaged waste water pump stations, NPSHa became easy for me to understand. I associated the dynamic of suction head available by thinking of the term available as synonymous with tools or means available. For example, nature supplies a means or tool for those of us concerned with suction head available in the form of our atmosphere. This important sphere (slightly more important as it supplies us with the oxygen we breathe) is an element in creating pressure head on the water’s surface and thus helping to create suction head available.

 

At sea level the atmosphere produces the same amount of pressure as a column of water approximately 30’ high.  Hydraulic modeling is something that is usually beyond the capabilities of station builders. When it comes to a Basic simulation of how a pump in a waste water lift station performs in relation to NPSHa ,(net positive suction head available) the station supplier can run some basic empirical tests.

 

The applications engineer can put the pumps through some differing suction head conditions that would apply to the hydraulic performance of the pumps under differing liquid levels in the waste water station. The packaged waste water station designer, as a professional in the industry, has to be concerned with cavitation and should attain from the manufacturer the NPSHr (net positive suction head required). In any “run up” performance test on the pumping operation cavitation is a paramount concern. The   potential for the temperature of the effluent in the waste water lift station to increase can affect the NPSHa.

 

It’s getting hot in here!

 

All liquids have a vapor pressure. Vapor pressure of a liquid is the transformation of a liquid to a gas. As the temperature of the liquid increases vapor pressure rises to the point of gas escaping in the form of bubbles or cavities in the liquid. These air pockets will collapse as they go from the low pressure vortex to the pressure stream. There is actually less NPSHr in the pumping of warmer water, but the challenge is to keep the fluid in its liquid form and warm water poses a challenge in this respect.

 

 In closing:

 

There are many mathematical equations that analyze fluid flow dynamics problems where cavitation may occur. Math formulas are tools that give the pump technician the ability to check the actual field and environment conditions against known mathematical values. Computing all the variables that contribute to cavitation in the submersible sewage pump can be done by a wonderful program called excell. So, to keep a waste water lift station pump on the positive side of suction head and positively produce a pump station with a long MTBF, let’s not get negative.

 

 

 

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See you at the Station- Lets make a Deal on a Pre-Fabricated Waste Water Pump Station

 For sale one “Taylor Made pre-fabricated Waste Water pump station”

Play along with me on this blog as I attempt to create the analogy in the sale of a used pre-fabricated waste water Pump station to that of the actions a person might take in selling their automobile. It is a comparison that makes one think.

 The public works manager or the asset manager should equate the regular maintenance of a pre-fabricated waste water pump station to its current  “used” value along any point of its life cycle. I can’t think of any method that is better to show the current value of a used asset, than to put it up for sale.

So, here we go, are you ready for your first buyer?

Our interested party is a very sophisticated customer named  John. John reads a lot of blogs, including “See you at the pump station” so he is really in the know. Now, our professional public works representative, who we will call Tom, is already a little rattled as he can’t find the “Pump Fax” report and he knows the buyer will want to see the work report on this 2007, Taylor Made prefabricated waste water pump station.

 Alas, at the last moment the work order logs are located, and after a look our customer states that the reports are well formatted. Tom is quick to point out that the detail in the paper work specifications from the inspection and work order sheets as well as the OSHA required confined space signage is included in the purchase of the Taylor Made pre-fabricated waste water pump station”.

John knows the value of the “Pump fax” report but is giving no sign that this station is the one. Being a good asset manager of this imaginary city , John wonders “who would find their financial situation so dire to have to sell a sewage pump station?’”

 

Tom kicks his salesmanship 101 into gear, and mentions the energy efficient motors that come with the purchase of the “Taylor Made sewage pump station”.  All the documents are there in the purchase order and its plain that Taylor Made Pump Stations, one of the few “Energy Trust” pump station builders with this designation, puts a great deal of emphasis in pumping optimization from both the hydraulic design as well as motor efficiency.

 

John finally nods in approval and almost shows his enthusiasm in this rare opportunity to purchase a low hour Top of The line Taylor Made pre-fabricated waste water pump station. Noticing this Tom moves on the performance aspect of the drives, which are likened to an Energy-Efficient “Gas Pedal” for electric motors, these speed controllers are of crucial importance in saving energy and reducing operating costs. The Taylor Made pre-fabricated waste water pump station, was specified for the pump supplier to utilize their controls and VFD’s for efficiency and single source responsibility.

The Taylor Made Pre-fabricated waste water station has both Brains & Beauty.

It was becoming plain to Tom that John was very impressed with all the features of the station as well as the maintenance records produced by the city. The PLC, with a Modbus connection provides all level control monitoring, status and alarm conditions notifications would be easy for his small public works department to learn and operate.

Now it is time to check under the hatch. John, had already done his homework on the 25HP submersible non-clog pumps and with under 1,000 hours on each pump he had little concern that the pumping ends and motors were of high quality and “top flight”(not to relate the pumps to the high quality brand of a similar sounding name, but excellent sewage pumps none the less).

The Taylor Made Pre-fabricated waste water station is also designed with easy clean in mind!

John, our  buyer couldn’t help but notice the bright red tube standing out at the top of the station. He recognized the Patented EZZ-Klean device as the asset manager of his city he had them installed in two of his pre-fabricated waste water pump station. He is very aware of how they increase the MTBF (mean time before failure) of the pump station. John said, “I really haven’t seen anything with this station that I don’t like. I cannot take the concrete wet well with me, but if you will throw in the top and hatch we can put the lid on this deal”. Tom, thought it would be a month or two before this sewer line was converted to a gravity line and thus the station could be decommissioned and removed. So If you’ll excuse the pun, it was a “crappy” deal but both men came out smelling good.

 

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