I was just about to respond to the untrue assertion that CARST is a part of AARST, but Bill beat me to it. Thank you Bill for responding. Yes - CARST is an entirely independent association with its own Board of Directors and Executive Director.

Bill, thank you for the correction that CARST is not a part of AARST. I got confused among all the AARST-related entities. But for a time at least, C-NRPP was run by AARST-NRPP:

From Fall 2012 AARST Radon Reporter:
The National Radon Proficiency
Program (NRPP) opened a Canadian
version of the credentialing program
(C-NRPP).

From the 2013 AARST Radon Reporter:
October 1, 2012, the NRPP certification program became
the AARST - National Radon Proficiency Program (NRPP)
in the United States, and the Canadian National Radon
Proficiency Program (C-NRPP) in Canada, both administrated
by AARST in its Fletcher Offices in North Carolina.

It also lists Pam as C-NRPP coordinator and AARST staff; she coordinates the Canada radon symposium currently.
C-NRPP Exam Coordinator
Pam Warkentin

From the Winter 2014 AARST Radon Reporter
Since 1986, AARST, the American Association of Radon Scientists
and Technologists, Inc., has represented radon professionals,
scientists and risk reduction advocates in the United States,
Canada, and all around the world.

AARST and CARST had a close relationship in the past. I found this history of CARST, and I thought it was interesting so here it is from its website archive:

September 2008
• Bob Wood and Pam Warkentin met with William Angell and the AARST board at the Las Vegas AARST conference regarding initiating a Canadian chapter of AARST.
• AARST were very supportive and interested in helping us proceed.
• We drew up a statement of intent at that time to start the process.
• Within a year, other Canadian members of AARST were starting to gain interest in the idea.

2009 - 2010
• We worked with the AARST chapter co-ordinator Nicole Chazaud and she provided us with support materials to initiate a chapter.
• We also approached the Canadian Radiation Protection Association (CRPA) and began a discussion to work together with them. CRPA set up a working group and decided that they would like to have a relationship with us, but we would require our own organization.
• We began discussions with a lawyer at the time and realized that in order to proceed as a Canadian non-profit corporation, we would need to start our own organization rather than be a chapter of AARST.

May 2011
• CRPA hosted a conference in Ottawa in May 2011 and offered us space to host a meeting to initiate our organization.
• We contacted all Canadian members of AARST to advise them of the meeting and 22 members met and became founding members of a new organization called: Canadian Association of Radon Scientists and Technologists (CARST).
• At that time we agreed on by-laws and set up a board of directors to proceed with incorporation.

April 2012 - The 1st Annual CARST Conference
• 45 people attended the conference.
• The agenda included presentations from individuals across the country on a variety of radon specific work.
• Health Canada presented an update on their cross country survey.
• NEHA-NRPP presented information on a new Canadian certification (C-NRPP) that they had just launched (April 1, 2012) to provide a Canadian version of the current American certification process.
• We also hosted a transitional exam which provided 31 certified professionals an opportunity to "Canadianize" their certification.

A call to action: Over the course of this coming year, let us conduct a field study by allowing US radon contractors to install 150 or more residential radon systems that vent at ground level.

We (the radon contractors in the field) could initially use only the most conservative of clearance guidelines when choosing (signing up) these homes for the field study.

These homes could not be part of a real estate transaction, for the contractor will need to maintain contact with the homeowners for initial and follow-up testing.

As with the Pennsylvania Re-entrainment Study, the radon systems could be set up to allow for extending the vent pipe above the roof line at the end of a year if the home owners desire or the follow-up testing indicates that it should be done.

We would need to design a study agreement that would hold contractors harmless during and after the study that would be acceptable to our insurance companies. I bet that the Pennsylvania study would have a model.

We would have to seek permission from state radon programs that have licensure.

If I have to return to a home at the end of the study period to run pipe up the side of the house, I will take that cost on.

At the end of a year we would have a good would have a better sense of how well the system perform across the country.

There are more deadlines for public review comments coming up, for mitigation standards-SF, LB, MF all together: MONDAY APRIL 18 snd APRIL 25. I know it seems pointless to submit comments, but there is a process to follow.

Hi. I posted a while back regarding how diagnostics allow us to use a 15 watt fan 97% of the time. For those of you who tried to connect with me I will be attending my first ever AARST conference in Bellevue in a few weeks. I'm co-presenting on Sunday a session called Gnarly Tales 2 where I have a 2.5hr slot to discuss how simple diagnostic tests can help turn a gnarly house into a nice house so you can go fishing instead of going back to put in a bigger fan. I really am looking forward to connecting with you guys and hearing about how you approach your jobs and also sharing my experience. Track me down and lets connect!

What time is your session? Sunday sessions are extra pay so can people audit (sit in without credit)? Do you have post-mitigation test data, from right after mitigation but also months and years after? thanks

MIchelle: The program on Sunday is a CE course and one can register for it through the AARST Symposium website. We are not able to accommodate auditors due to size of room and number of attendees so far.

I don't know how to admit this but i missed this whole discussion as it came forward. As another Canadian mitigator who was originally trained and certified as a NRPP mitigator (Dallas taught my first class for measurement certification) , change driven by science is the best .
As part of the team that helped to start CARST supported by AARST in so many ways we owe you in the US big time.
That does not mean that the child does not hold different opinions than the parent, i had initially told Rob Mahoney, back in 2007, that i did not see a time where my company would support a rim wall discharge.... today 99% of our fans are indoors and discharge through rim joist. 90% of our fans are 20 watt fans with radon reductions into the below 1 pCi/l many of these fans operating in the 5 watt of power usage.
Colin has become a radon mitigation leader in Canada and around the world, and it was his class at a CARST convention that i saw the science of communication testing and fan sizing, I could not believe how simple it was. We do it every time now and get our clients to help. They love that we demonstrate the science we use to size their fan. It is now a science that they believe in, they believe in us as a radon mitigator, and they have a reason beyond price to tell their friends to choose us.

Let's pretend for a minute that you want to make the most amount of money you can on a radon mitigation ( i know i do).
Lets compare two teams team 1 shows up in slovenly clothed, rusty van with dusty tools shop vac that is the same as the one in the garage. Team two shows up in a wrapped or lettered Van, wearing uniform that while and it has some glue drips or caulking on it is clean and they use a drop cloth shiny metal shop vac and spend 5 min bringing in their tools in tool boxes and the first thing they do is ventilate to protect from high levels of radon exposure to the workers. do you care what the second team is charging ? My clients don't. We show them the science as we are doing it... if they are interested...most are. What are they going to tell their neighbours? Are they going to keep high radon (their dirty little secret) or are they going to tell their neighbours?
# 1 tool - Radonaway's little red grab sampler GM-1.. sub slab radon is typically 10-100 times the radon in the house... even if they dislike their next door they do not want them to die they tell them ..... I get another job
if you as a mitigator( or your team ) show up in track pants and running shoes with the same tools as the homeowner has, don't ventilate to protect your worker from radon exposure and don't do communication work to prove you are a skilled trade you are maybe you only deserve what you are getting for your work.
i apologize for my rant but low priced competition bugs me.
i started out to write this post to encourage you to attend Colin's seminar at ARRST and if you want to get on his good side and maybe want him to train at your local areas talk about the fishing in your local area's I got him onto fishing for small mouth and largemouth bass this summer at a northern Ontario pickerel/pike lodge, and he cannot wait to do more, ask him about sturgeon fishing in BC ( he landed one over seven feet!!)
Bob W