Water Environment Federation (WEF) Discussion Forums / WEF Discussion Forums / Utility Management

Mapping Various Pipe Materials

Fred S. — Thu, 01 May 2008 16:21:22 GMT

If this has been discussed before, just point me in the right direction.

Just wondering what naming convention other cities use when labeling pipes on their GIS mapping systems. In recent years, the number of different types of pipe materials is increasing, plus there are lined pipes with various liner materials.

Do you label the host pipe material AND the liner material? Do you identify if it is a 'burst' pipe? Do you differentiate smooth pipe vs. ribbed pipe. For example,various spirals and profiles exist and many are not compatible in terms of fittings, etc. which becomes problematic for field crews doing emergency repairs.

Labeling everything makes for a cluttered map; however, relying on asbuilt drawings for everything has its own issues.

Fred

RE: Septic to Community Sewer Conversion Financing

sewerguy — Thu, 01 May 2008 13:56:03 GMT

We are in the design stage of a sewer extension project that will serve 266 existing properties and 305 future customers, for a total of 571. The estimated cost is $9 Million. The Authority that is constructing the extension has determined it can pay $3 Million of the cost, or about 1/3 of the $9 Million cost. The $3 Million is what the Authority can pay and not raise rates for its other 31,000 customers, based on the cost of the extension and the projected costs and revenues from the 571 customers over a 20-year time period.

Based on the 571 customers paying $6 Million, the cost per customer (Special Purpose Fee) will be about $10,500. The Authority is willing to finance this over time, but the residents are still very upset about the cost. The residents are looking to their municipality for assistance to pay.

Septic to Community Sewer Conversion Financing

Warner — Thu, 27 Mar 2008 12:26:04 GMT

Desire feedback regarding how other utilities may be assisting individual homeowners, which have a failing septic system, to finance conversion from the septic system to a community sewer system.

Our utility presently does not offer financing plans to individual homeowners (i.e. monthly surcharge to the utility bill). Individual homeowners are responsible to pay all sewer connection and construction fees in advance, which can be upwards of $15-$25,000 per home.

Our community has successfully advanced larger community projects (200-300 homes at a time) with grant and SAD funding - but we struggle with finding ways to help individual or smaller groups. Thanks in advance.

RE: Determining staffing levels for wastewater treatment plants

ashleywilson — Wed, 23 Apr 2008 02:40:04 GMT

Hey M.Gingras ,
are you looking any reference material or information on how to determine staffing levels for wastewater treatment plants? so few days ago i was searching about wastewater treatment plants so i found a website http://www.jnblabs.com/ i got allot knowledges for my research papers.

Determining staffing levels for wastewater treatment plants

M.Gingras — Thu, 15 Sep 2005 15:45:59 GMT

I am looking for any reference material or information on how to determine staffing levels for wastewater treatment plants.

Thank you

RE: Septic to Community Sewer Conversion Financing

Jerry — Thu, 27 Mar 2008 14:13:53 GMT

If you try to charge home owners a large cost like that, they will fight you. It would be best to find Grant money or low interest loans payable through user fees.

RE: KwH per pound of BOD removed

Deerfield Wastewater — Wed, 19 Mar 2008 15:56:36 GMT

Interesting question. Ours is 1.1-1.2 kwh/lb BOD but that's for the whole plant, not just aeration. We have floating mechanical aerators and just one electrical meter for the whole plant. We have also been tracking sludge disposal cost per pound of BOD treated in case anybody is interested. For us that's about $60/lb BOD.

KwH per pound of BOD removed

Mickey Nowak — Wed, 02 Jan 2008 14:50:08 GMT

Does anyone keep track of this? I am trying to track energy used by the secondary treatment process. I have some calculations that show 0.5 to 1.0 KwH per pound of BOD removed. Does that sound right?

RE: Benchmarking

Fort Collins Ravi — Tue, 11 Mar 2008 21:05:42 GMT

Greetings!

For additional information you may wish to review the Qualserve website at:
http://www.awwa.org/Resources/utilitymanage.cfm?ItemNumber=3766&navItemNumber=1587

It has a lot of information on benchmarking that w and ww utilities can use.

Ravi

Benchmarking

KW — Wed, 02 Jan 2008 14:17:04 GMT

What values/benchmarks are normally utilized/measured for a Wastewater Utility.

We operate a 7.25 MGD plant and associated Collection System. This is the first year we have been asked to start the Benchmarking process. I am familiar with the concepts and have halfway educated myself. My concern is that we identify common and useful values to benchmark with.

What values should we start with?

Any comment or assistance will be appreciated.

Kurt Williams

RE: Treatment Plant Equipment Availability, Reliability and Redundancy

Bill H — Fri, 08 Feb 2008 11:12:58 GMT

For the most part redundancy is to prevent the discharge of untreated wastewater. So, if you have a clarifier go down your back up will save the day. That is a State requirement. You must treat the incoming wastewater with existing equipment you have. You could be using all your clarifiers but if one goes down you must still be able to treat the waste.

Treatment Plant Equipment Availability, Reliability and Redundancy

01780898 — Thu, 17 Jan 2008 00:10:30 GMT

Can anyone suggest relevant documents/standards on the equipment availability, reliability and thus redundancy for large wastewater treatment plants (1 million ep).

I have found the WERF report and the SMRP. Are there any other protocols or recent emperical standards?

Thank you

Grant H, Australia

RE: Treatment Plant Equipment Availability, Reliability and Redundancy

Grant H — Fri, 08 Feb 2008 06:28:31 GMT

Yes thanks, the WERF report directed us to the Ten States Standards. Currently 2004 edition and is now $12.

The WERF report was a bit disappointing as it was a survey of current practice. No framework

The USEPA Report is 1974, so I don't think it would be that useful - back in those days governments were putting lots of money into cleaning up wastewater. There used to be plenty of redundancy and instrumentation was totally different.

RE: Treatment Plant Equipment Availability, Reliability and Redundancy

John Sansalone — Fri, 25 Jan 2008 19:03:06 GMT

Another reference that you may find useful is the "Recommended Standards for Wastewater Facilities", which is put together by the Great Lakes-Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers (whew ! That's a mouthful). It's usually referred to as "Ten -States" standards, due to its origins (Illinois, Indiana, Iowa, Michigan,Minnesota,Missouri, New York, Ohio, Pennsylvania, and Wisconsin), but now also includes Ontario. In N.Y., it can be bought from the Health Education Services, which acts sort of like a government printing office. I assume it is similarly available in the other states, and guess that the cost is about $10. Can probably find out more details on-line.

RE: Treatment Plant Equipment Availability, Reliability and Redundancy

Jeff Naumann — Fri, 25 Jan 2008 12:30:01 GMT

You might want to get the following design manual from WEF:

Design of Municipal Wastewater Treatment Plants - MOP 8, 4th Edition

My much older (1977) version is very straightforward regarding all of the important aspects in sewage plant design, including the need for backup equipment. I assume that the current version is equally helpful.

RE: Treatment Plant Equipment Availability, Reliability and Redundancy

TerryF — Thu, 24 Jan 2008 17:39:44 GMT

The US EPA and a number of US states publish documents with general guiding principles regarding reliability , redundancy and emergency capacity. If you apply the principles , use a sensible risk management approach , and talk to some smart and experienced operators and maintenance personnel then you will probably get the result you want.

Process flexibility helps.

Regards

TerryF

RE: Recovering blower heat during winter

seeker — Thu, 24 Jan 2008 17:28:03 GMT

Grant H,

Thank you for your reply and suggestions. Some time has passed since I posed this question and my thoughts have gone to different possibilities.

I am now leaning towards finding some way to insulate the pipes or tubes that carry air to the diffusers. Although some of the piping is subterranean, some is above ground. My caution is actually due to the volume of the total aeration basins (two trains of 4) so I would at best hope to impact the first aeration basin in each train. Right now we are clipping 10 degrees (+ or - 1) C...things are a bit slow going until a warm up in the spring.

What do plants in the farther northern reaches do? Cover? Enclose?

Mike

Recovering blower heat during winter

seeker — Wed, 05 Dec 2007 16:06:25 GMT

This is the first forum topic I have submitted, if it has been addressed elsewhere, I apologize.

I am interested in trying to recover heat from a pair of 75 hp Lamson blowers to hopefully add some degrees of heat to aeration tanks in the winter. Does anyone have any experience in this?

Is it feasible and effective to channel vented, heated air into the tanks? Currently, the heated air is released (wasted?)to the atmosphere.

Is it more feasible to use a collection system of copper tubing to capture heat from the in-building portion of the duct, then to use a vinyl/butyl tubing construct in the tank to heat the liquid, the heat carried by a circulating glycol-water mixture?

Is there a heat transfer unit that could survive immersion that is not stainless steel?

Are covers (solar or pool-like covers) the more efficient way to keep heat in or heat aeration tanks?

I know these are several questions, but would appreciate any feedback. I'll check back tomorrow (Thursday, 12/6).

Thanks,

Mike

RE: Recovering blower heat during winter

01780898 — Thu, 24 Jan 2008 07:49:05 GMT

Yes there is quite a lot of heat going into your aeration tank with the blower air. But what happens to all this heat? I believe the answer is that the air leaving the top water surface level is as saturated as the ambient wet bulb temperature. So your aeration tank will never get any hotter than the hourly/daily wet bulb temperature. In northern parts of the US this is pretty low in winter. If you get hold of a psychrometric chart you can use weather service temperature and rel humidity data to work out what the wet bulb temperature is.

Now all that is good for aeration tanks with blower air. If you have surface aerators they actually do not put any heat into the wastewater and a source of heat may be useful. Two small blowers would probably not significantly heat up your aeration tank. Get a chemical engineer to work out what the heat input divided by the flowrate of wastewater through the tank to give you an idea of the temperature rise. It should be able to be done on the back of an envelope.

Regards

Grant H

RE: Treatment Plant Equipment Availability, Reliability and Redundancy

01780898 — Thu, 24 Jan 2008 07:36:15 GMT

Yes redundancy includes all TP equipment, from tanks, pumps and pipework, PLC, instrumentation and control equipment.

Obviously each item has different redundancy requirements (e.g. flow treatment equipment must be sized for PWWF, whilst sludge pumps need redundancy but operate at one loading).

RE: Treatment Plant Equipment Availability, Reliability and Redundancy

D Shulmister — Fri, 18 Jan 2008 12:57:59 GMT

Does "equipment" include treatment tankage?

RE: Benchmarking

KW — Tue, 08 Jan 2008 09:02:51 GMT

Thanks for the information.

It will get me started. I would anticipate needing to look at the indicators or values measured to get a good grasp on what they all mean to us.

Kurt

RE: Benchmarking

Wiff P — Fri, 04 Jan 2008 12:49:40 GMT

$/MG and kwh/MG are nice general "benchmarks" but of course the challenge with these sorts of benchmarks in comparing them plant to plant is the great variety of configurations to the plants including collection system components. One good way to start into benchmarking is to find 2 or 3 wastewater plants which are similar to yours and network with them to compare how you do things, what your relative costs are for different things, how you staffing compares, how you manage your system, etc. noting unique challenges as well as commonalities you have. The place to compare is where things are common and benchmarks will suggest themselves from that process. You may find that you do some things very well and they do other things very well and all can improve from the process.

Another way to use benchmarks is based on your own goals- where you look to improve for example. If getting more energy efficient is important than you may want to set up some energy use benchmarks either per month, per MGD, or if you have metering by areas, usage per area. If a key cost component is sludge disposal you might want to benchmark sludge cake concentrations, sludge loads hauled per month, or on similar factors. Food for thought.

Wiff Peterson

RE: Recovering blower heat during winter

seeker — Fri, 04 Jan 2008 09:33:48 GMT

Thank you for the suggestion.

I have not looked into floating balls, but will research them now.

Also, a more efficient method of keeping heat going to the basin by insulating the blower pipes leading to the aeration chamber is being considered.

RE: Benchmarking

D Shulmister — Thu, 03 Jan 2008 15:58:13 GMT

One of the "easy" values is $ per Mgallons. Divide the month's (or year's) expenditures by the month's (or year's) total million gallon flow. Similarly, divide the electric consumption (or bill) by the flow to get power ($) per MG (etc.) Other benchmarks might be pounds (or tons) of biosolids produced or disposed per MG.

RE: KwH per pound of BOD removed

TerryF — Wed, 02 Jan 2008 16:08:34 GMT

Mickey,

Keeping such data is useful as a historical record of performance within your own plant , but unless you are comparing yourself to a plant with similar characteristics in terms of configuration , operating parameters , effluent goals and influent characteristics , then it maybe of limited value. For example a plant with surface aeration might use substantially more energy than one with fine bubble diffusers for the same throughput and effluent goal.

Nonetheless in the big picture such data from a large number of plants is useful to see trends in the industry in terms of efficency , impacts of licence changes , the effects of technology change etc.

I did a quick calculation and on average we are doing about 0.9kwh/lb BOD removed operating for low levels of N and P with fine bubble diffusers.

Regards

TerryF

RE: Recovering blower heat during winter

Rotifer — Tue, 11 Dec 2007 13:50:51 GMT

Mike, Have you looked into using floating balls? I understand that they are used in lagoons in the western states.

RE: "Evaporation Credits" for Commercial Laundries or other industrial customers who "Lose" water in Process

potwlab — Tue, 11 Dec 2007 12:18:28 GMT

If you use wastewater meters to measure the effluent from an industrial/commercial laundry, be aware of the limitations of the wastewater measuring device. The material in laundry effluent such as surfactants, other foaming agents, temperature,and flow variations can greatly impact the measuring capabilities of ultrasonic flow devices and mag meters. We have a comprehensive industrial effluent billing program and use wastewater meters in many industrial applications. Attaining accurate industrial laundry effluent flow measurements are one of our challenges.

"Evaporation Credits" for Commercial Laundries or other industrial customers who "Lose" water in Process

01141046 — Tue, 27 Nov 2007 14:41:51 GMT

Are there any utilities that give a discount on the sewer charges because of water that evaporates in the business process? I have some large commercial laundries that claim that 15% or 25% of the water entering the facility is evaporated and does not enter the wastewater system - therefore the wastewater bill should be based on that reduced amount - not on the amount of water that goes through the meter.

Are there utilities that provide this type of "evaporation credit"? Does your sewer ordinance or your set of regulations address these circumstances?

Thanks!

RE: Recovering blower heat during winter

seeker — Fri, 07 Dec 2007 10:22:03 GMT

Thanks again for the response and great questions.

I agree that any cover cannot be tight, but my initial thought is that the evaporative surface area could be reduced, cutting the loss of heat.

I will continue to think and research some alternative approaches.

Mike

RE: Recovering blower heat during winter

TerryF — Thu, 06 Dec 2007 16:08:32 GMT

Mike,

What is going to happen to the solar covers when the aeration starts up?

Further to my previous post , a substantial quantity of the heat generated by the blowers already go into the basin via the airflow through them. Try touching some of your aeration pipework.In fact many blowers have temperature , pressure, airflow limits on them designed to limit heat build up. Usually minimum airflows are specified to ensure adequate cooling.

Regards

TerryF

RE: Recovering blower heat during winter

seeker — Thu, 06 Dec 2007 12:09:39 GMT

Thanks, TerryF.

Our WWTP is small @ 355,000 gallons (current flow about 170,000)...Aeration tanks = 8 times 20,400 gallons or 163,200, but I would looking at only 1/2 of that, one train of 4 or maybe just impacting a single tank. Still, I can understand the 100 gallons vs 20,400 gallon challenge in trying to raise a couple of degrees.

I actually started looking at some solar pool covers since the aeration tanks are open to the sky, when I got the idea of using wasted air from the blowers in conjunction with a winter cover. I figured that the increase might be incremental, but am not aware of loss via transfer, how to convert the BTU and temperature of the vented air to a quantitative view.

The current operation is 1 hour on and one hour off for the 75 hp blowers (good electric savings and seems to help the process), i.e., they are not constantly on, so I was already at a 50% point. Our smaller digester and surge/equalization tank blowers (25 hp) are on for 24/7.

So, I reckon that I will go back to researching covers. Thanks again.

Mike

RE: Recovering blower heat during winter

TerryF — Wed, 05 Dec 2007 22:33:08 GMT

Mike,

Great idea , but unfortunately the numbers don't add up. The amount of heat coming off your blowers is not enough to make any real difference. I can do the math if necessary to show this but in simple terms i would suspect that the amount of heat given off 75 hp blowers would be no more than the equivalent of 10 hp or 7.5 kw. If you have an electric water heater in your house its probably in the range of 2.2 to 7kw (give or take a bit) and it heats maybe 100 gallons if that. I don't know how big your aeration tank is but with 75hp blowers i would think they could be 0.25 to 0.75 million gallon or more. Given the heat losses from the aeration tank is quite high by the constant mixing the amount of difference the heat from the blowers will make will be unnoticeable.

However it is great that you are thinking things through and looking for opportunities to improve. Afterall this is what the forum is about.

Regards

TerryF

RE: "Evaporation Credits" for Commercial Laundries or other industrial customers who "Lose" water in Process

D Shulmister — Thu, 29 Nov 2007 12:26:12 GMT

Jeff and John both make excellent points (as we've come to expect.)

One other direction that could be considered is a flow meter on the discharge piping. This would give the utility a fairly accurate number upon which to bill sewer charges.

RE: "Evaporation Credits" for Commercial Laundries or other industrial customers who "Lose" water in Process

John Sansalone — Tue, 27 Nov 2007 18:50:37 GMT

I think Jeff makes a good point about the water loss, but there is another factor you may need to consider : large commercial laundries also tend to discharge very hot water, at a high pH. One local village I know of used to get pHs of 10 - 11 in the collection system, and a temp. close to 200 deg. F. In another case, I know of a laundry that routinely dumps slug loads of solvents into the sewer system, whenever they wash the rags used to clean the printing presses of a regional newspaper. The impacts of these things at the "back end", may warrant surcharges that offset the savings in water usage.

RE: "Evaporation Credits" for Commercial Laundries or other industrial customers who "Lose" water in Process

Jeff Naumann — Tue, 27 Nov 2007 17:02:14 GMT

The Sanitation Districts of Los Angeles County in California does give almost any kind of credit that can be demonstrated. Laundries do in fact evaporate water in that the washed clothing, towels, sheets, etc. go into the dryers in a wet state, where all of that water is evaporated. I don't know what fraction of the purchased water, however, is in fact evaporated. That would probably vary, depending upon how wet the material is when it goes into the dryers, which would in of itself depend on what the fabric type is. Other equipment can also be allowed an evaporation credit, such as boilers, cooling towers, etc.

RE: Regulated Minimum Number of Operators

D Shulmister — Mon, 19 Nov 2007 12:43:03 GMT

Wiff P (11/16/2007)

This is a very complex issue and difficult to fairly regulate in my view as each facility and owner's organization can be quite different in staffing needs and approach. Ultimately needs are very site, operations organzation, and system specific.

This is absolutely true!!

I have a plant which is designed for 11 mgd, but the flow is only 4 mgd. I'd hate to think that the EPA or state regulators would want to direct the staffing level for that plant based on the design, especially since (nearly) no one with EPA nor the state has a clue about plant operations. The state should set a mininum number of operators, e.g., one licensed operator per shift. The utility should then have the latitude to add to that minimum, not be forced to add personnel which are not needed. On the other hand, utilities need to be responsible in setting staffing levels, not based on budget constraints.

Regulated Minimum Number of Operators

kroush — Thu, 28 Jun 2007 12:40:22 GMT

The State of New Mexico is developing regulations that will require a minimum number of operators for water and wastewater facilities. I was wondering if other states have or are considering similar regulations.

RE: Regulated Minimum Number of Operators

Wiff P — Fri, 16 Nov 2007 15:02:47 GMT

This is a geat question to take to ABC (Associated Boards of Certification) as state certification authorities typically get involved in this issue. You can find them on the web.

To my experience it seems each state handles a bit differently. Massachusetts for example indexes staffing to the O&M Manual prepared by the plant designer while recent efforts at many plants have focused on becoming more cost efficient which typically also involves looking at plant organization, shift schedules, outsourcing some services, etc. for larger plants. NEIETCC, here in New England, is currently working with EPA to update their wastewater system staffing manual and they are due to finish that effort this winter or spring. That will give you some guidance in your efforts when it is done.

RE: Tiered User Charge Rates

Wiff P — Fri, 16 Nov 2007 14:53:25 GMT

You may want to look at estimating the marginal cost to treat their waste first. Separate your fixed costs from your variable costs. Then estimate what you would save if they pulled out of the system (the marginal cost of treatment being the avoided cost). Think about what's fixed and variable first then check it by seeing what truly "goes away" should they move away. Next see what that gives you for a user rate and how it compares to current rate. Ask yourselves if you can afford to use that rate for all users? Essentially owners of the system would pick up fixed costs and any ndustrial users would only pay their variable (added) costs. Any system has to be equally fair to all users including public (considering perhaps added value of industies in other respects). Also consider whether the industry has been a good corporate citizen vis a vis the treatment plant. Do they pose risks to effluent quality? Problems for sludge handling or other areas? Are they responsible users of the system and cooperative with wastewater personnel? This process should lead you to a good decision about what to do.