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AQS "Ask the Experts" August 2019

A presentation on linked sites was given by Robert Coats.  Linked sites is the ability in AQS to calculate a complete design value for Ozone and PM2.5 for sites that have moved or have their time series otherwise linked to another nearby site.  Only EPA staff can link a site.  If you need to link sites, work with your regional contact.

Q: Since PM2.5 has a quarterly requirement, how will the new linked function handle monitors where the second monitor became active several months after the initial monitor closed? Ex. 2nd monitor opened at the end of 3rd quarter when the initial monitor closed at the end of 1st quarter.

A: The linked sites are treated as a single site for “time series” purposes.  That is, the data from the old site is pre-pended to the new site for the DV period.  It would be handled the same way as a similar gap at a single site.  (Calculation details for this case omitted.)

Q: Would primary and satellite PM2.5 samplers from the same site need to be linked in order to get a DV (e.g., a primary POC-1 1 in 6 linked with a satellite POC-11 1 in 6 where they're offset by 3 days?

A: If the monitors are at the same site, the concept of linked sites does not apply.  This would be handled as primary and non-primary monitors the way AQS has done up to the present.

Q: To get a report of linked sites can you select more than one state and can you get a pdf report of the results?

A: The DV report will do this automatically if the link sites option is selected.  [I missed / did not understand the rest of the answer to this question.]

Q: What is the status of the API for AQS?

A: The version 1 API will be retired soon.  The version 2 API has been up and running since November and is available for use.  The landing page is accessible from the AirData page.  People have been transitioning since early in the year and we’re about to add more memory to the host computer to keep up with the demand.

Q: What’s the link for the API version 2?


Q: Is there any news concerning implementing changes AQS from the 2016 Exceptional Events Rule? Haven't really heard anything new since the 2017 EER Workgroup.

A: These have been on the docket, but we’ve been without a support contractor since then and have not been able to get to that work yet.   We will implement it as soon as we can.

Q: When I load [PM]2.5 data, I also load the 68101-109 codes because they are in our strings from our software. What I end up getting is a few hundred pages of warnings (“Collection Frequency Code was ignored.”) mixed in with some possible errors. Is there a way around this? 

A: Not currently.  We do have a pending request to allow users to suppress warnings (rather than errors) in the load report and that will be possible when we make that change.  The work around is to search the PDF for the word “Error” to find the errors mixed in with the warnings.

Q: Where will Zero/Span data be inputted into AQS?

A: We have a batch transaction for submitting that data (QA – Zero Span) that can be submitted like any other data.  The data coding manual and transaction format descriptions have details on constructing.  There is also a form where it can be entered manually (like other data). 

 Q: Any update on using Qlik for reports? / What is the status of the AQS Reports section? We had a productive workgroup on addressing concerns and ideas using Qlik. 

 A:  We’ve run into some deployment speedbumps with Qlik.  We’re working to get those resolved and, at the same time, investigating alternatives.  The work that’s been done will be used no matter what technology we end up with. We’re still looking to have at least some reports available in calendar year 2020, but don’t have details at this time.

Q: When will the AMP 300 report be updated for the ozone NAAQS standard of 70 ppb?

A:  The report defaults to the 2008 standard.  That is a mistake and we will change it to default to the new standard.  Until we get it fixed, you can manually change the standard in the options tab to get the correct results.

Q: When will the next QA eye come out?

A: We’re not sure.  There group that publishes it has gone through major changes.  We’ll pass on the question.

Q: Is there an update on the removal of screening groups and the use of agency roles?

A: This is another project that we’ve tabled to make room for critical work.  We’ll get back to it as soon as we can, but are not sure when that will be.

Q: Will all the Q&A information from today be available on the AQS Website (much like the November 2018 webinar)?

A: Yes


We are reviewing the metadata required for site and monitor creation with the goal of making AQS and the network monitoring plan requirements to align better.

Related to metadata changes, AQS still has old MSA information in it, but this is no longer a valid area definition by the Census.  If you find old data with MSA (for example, in monitor objective / area represented) and you want to modernize it, please update to use CBSA or UA (urbanized area) instead.