OT: Compliance requirement for annual "calibration"

I wonder how people here handle such a requirement.

So in one of our plant out in rural area we discharge wastewater directly to the environment and we have a permit for that. I believe (to be verified) that the water are byproduct of boiler water regen process so it's quite clean to begin with. Anyway, the discharge permit call for annual calibration and keeping of cal record but there's no elaboration of acceptable method.

Right now the meter is an old peddle-wheel type on a 3" line and I have the option to upgrade it to something more modern IF it would make it easier to satisfy this requirement.

The question is, how do you folks handle this type of compliance requirement?

What is your flow rate? Can you start and stop the flow at anytime you want or does it have to be flowing continuously? How accurate do you need to be? +/-.5%, 1%, 2% ect.

If you can start and stop the flow, I would look into a Seraphin Can for calibrating the meter. The size of the can will be determined by the flow rate. Normally about 1.5 times your max flow rate is a good size to look for.
If you cant start and stop the flow then you might want to use a Master Meter to calibrate the flow meter. The Master Meter will need to be calibrated at a lab or facility that can handle it.

This one is in my "Wheel House" as meter calibration in the Petroleum Industry is the main service my company performs

harryting said:

I wonder how people here handle such a requirement.

So in one of our plant out in rural area we discharge wastewater directly to the environment and we have a permit for that. I believe (to be verified) that the water are byproduct of boiler water regen process so it's quite clean to begin with. Anyway, the discharge permit call for annual calibration and keeping of cal record but there's no elaboration of acceptable method.

Right now the meter is an old peddle-wheel type on a 3" line and I have the option to upgrade it to something more modern IF it would make it easier to satisfy this requirement.

The question is, how do you folks handle this type of compliance requirement?

Click to expand...

We had two mag flowmeters that would be swapped I think it was every 6 months. The in use removed meter would be sent in for factory cal. So each meter would be in the cal system and a reminder sent out for swapping. The EPA was fine with this procedure.
The discharge line was I think 6" with a typical flow of 800 gpm. Since it was from one of three holding ponds from our Industrial Waste Water Treatment Plant we could shut down the flow as needed. It was also restricted to discharge only when the river was flowing fast enough per EPA guidelines.

The easiest is to have a second meter that you can send it to have calibrated. That way the inuse meter is always calibrated with a cal certificate from where ever you got it calibrated at. You may also need to calibrate you analog input, for this you would need a calibrated source supply.

Thanks all to the good info. I'll schedule a site visit to get more information.

There's no accuracy/precision requirement in the permit (issued by State Ecology dept) except there's a daily discharge limit and it says "metered or calculated" which doesn't scream high precision to me. I'll also check with our compliance person to see if there's any insight on it.

The water/waste water (w/ww) industry generally accepts "Verification" of magmeters, which is a process that assesses whether the meter performs within a tolerance band of its factory-new performance.

Siemens uses a stand-alone 'verificator' which tests the electronics separately from the tube's coils and magnetic field. The verficator reads the factory performance data from the tube/electronics memory and compares it to the data it gets during the test. The verificator then passes or fails the tube and/or the electronics.

The test is done in place, with the only requirement that the tube be filled with liquid. There's does not need to fluid to be flowing, it just needs a full tube.

The verificator eliminates the need for removing and sending the tube and electronics off to a cal lab that has a flow stand.

The Verificator itself is pricey and the end users typically buy the verification service from a provider.

I'm sure that other manufacturers in the w/ww market must have similar abilities.

We have technicians that go out and provide calibration services. For flow meters, they typically fit their calibrated meter in line with the customer's and then pass a certain volume through both. Then they just adjust the customer's to match.

This way, there is usually no removal of the existing meter. It can be very easy to fit their meter in the line if there is appropriate valving provisions made.

Glad to see that this is not only a problem in the UK. We have a similar permit and it mentions continuous monitoring, but no detail over what they consider continuous. I asked their auditor and was pointed to the permissible errors and limits, but nothing on what continuous means to them. Is it 1 sample per hour? 10 per second? No one knows...

In your case, and having been involved with similar discharges to a river, the main concern was actually the temperature of the water. The water was clean unless a breakdown occurred, but the temperature that it came out of the process was much higher than the river (obviously) and they allowed only a certain window between river temperature and discharge water.

I can not really answer, but this is similar to rules that need to be followed for CE / ISO standards i think. I have a new position as automation responsible for a small machine. In our case some of the processes need only be documented, i think this is for ISO. So, if we document a really crappy process, it's all good. For CE i think there are more absolute rules, so in my case I would try to ask the inspector. If that is possible, I know all standards are behind expensive pay walls.

I looked at "Ten States Standards" ( http://10statesstandards.com/wastewaterstandards.html ) and found nothing.

If you are discharging directly to surface water you must be covered by a discharge permit issued by the state. ( https://ecology.wa.gov/Water-Shorelines/Water-quality/Wastewater ) In most cases a 1% accuracy is going to be good enough. Your turbine meter is probably good enough.

I suggest you have an outside instrument calibration guy come in once a year and issue a certificate that he has done a calibration check. Keep that on record. For additional guidance I suggest that you contact a couple of local municipal treatment facilities in your area and ask them. Wastewater professionals are among the most helpful guys I know, and they can probably tell you who they use and what their procedure is. Write it out, so if the state guys ever give you grief you can document good faith efforts.