How do I close a QA Collocated monitor?

First, users need to understand there are several business rules that dictate the process for closing out a QA collocated monitor and setting one up.  We will walk through the process below using an example.

Scenario:  The user has a site with three monitors, we'll call them POC1, POC2 and POC3.  All of these monitors measure for PM_2.5.  POC1 was set up as the NAAQS QA Collocated Primary monitor, POC2 was set up as the QA Collocated Secondary monitor and POC3 was set up as an extra monitor.  The user wants to make POC3 the Primary NAAQS and QA Collocated monitor and keep POC2 as the QA Collocated Secondary monitor.  To do this, the user needs to unwind the current setup, but you cannot do that in one step and it needs to be done in a certain order adhering to the business rules.

Business Rule:  Certain NAAQS parameters (PM_2.5, Ozone, NO₂ and Pb) are required by the regulations to have a primary monitor designated at every site where you monitor those pollutants for NAAQS determination purposes.  Note: If the primary monitor takes a sample for the day, that is the site value for the day, if it doesn't take one, then any other monitors for that parameter at the site are averaged to give you the site value for the day.  The primary monitor is designated on the Maintain -> Site form using the Primary Monitor Periods tab.  For QA monitoring purposes, for monitors sampling PM_2.5, PM₁₀ or Pb and anything else that collects samples on a filter, (i.e. PM_2.5 has a requirement that 15% of the PM_2.5 monitors have to be QA Collocated).

In our scenario the first monitor (POC1) is the QA Collocated Primary monitor and is used for regulatory purposes.  The second monitor (POC2) is the QA Collocation Secondary monitor and is used to check the validity in terms of accuracy and bias of the QA Collocated Primary monitor.

Business Rule:  The QA Collocation Primary monitor must be the same as the NAAQS Primary monitor.  The QA Collocated Secondary monitor is the one you want to use to check whether the Primary QA Collocated monitor is correct or not vs the data quality objectives in the regs.

Business Rule:  If a QA Primary has a QA Collocated monitor,  you can't discontinue the QA primary until the QA Collocated has been discontinued.  (Discontinued means either totally closing the monitor by placing a Close Date on the Monitor Basic tab and saving it, or leaving the monitor open by placing an End Date on the QA Collocated tab and save it.)

To unwind the current scenario the user must:

1. Discontinue the QA Collocated Secondary monitor by going to maintain -> Monitor -> QA Collocation tab for POC2 and adding an End Date and click on Save.
2. Next, go to Maintain -> Monitor -> QA Collocation tab for POC1 and adding an End Date and click Save.  Now the Primary QA Collocation monitor is no longer QA Collocated and it is simply the NAAQS Primary monitor.  Remember: PM_2.5 et al must always have a NAAQS Primary monitor.
3. Before you can close the NAAQS Primary monitor (POC1), you must designate POC3 as the new primary.  To do this go to Maintain -> Site -> Primary Monitor Period tab and add an End Date for the current primary monitor (POC1), then add a Begin Date for the new primary monitor (POC3) and then click Save.  You must save both at the same time to ensure you always have a Primary monitor.
4. Now POC3 is the new NAAQS Primary monitor, POC2 is an extra monitor and POC1 is an extra monitor.  But in our scenario, this site has been identified in the Annual Monitoring Plan as a QA Collocated site and since POC3 is the new NAAQS Primary monitor for the site, that is the monitor that must become our new QA Collocated Primary monitor.
5. When setting up the new collocation monitors you must first setup the QA Collocation Primary monitor before setting up the QA Collocation Secondary monitor.  To make POC3 as the Primary QA Collocated monitor using Maintain -> Monitor -> QA Collocation tab, enter a Begin date, click 'Y' in the Primary Sampler? column, and click Save.
6. Finally, you use Maintain -> Monitor -> QA Collocation tab for POC2, add a Begin Date, enter the distance from the Primary Sampler and click 'N' in the Primary Sampler? column then click Save and you are done.