There are many well thought out comments on this page.  In regard to required certifications and training it’s simple: 

There is no way to provide a residential or commercial clients with a proper indoor air quality assessment to include a detailed report, discussion of contamination, location of cause and a remediation protocol without having  at minimum the following training:

WRT, AMRT, CIE and Home/ Building Inspection Certifications

Providing a certified scope of work takes a lot of knowledge which includes:

Understanding of the water restoration industry

Understanding of microbial contamination

Understanding of building science, construction and inspection techniques

Each one of these categories are already a stand alone industry and a person that has a combined knowledge of all three is the only person that should be advising I.A.Q. clients about where mold is growing in a dwelling, what is causing the contamination and how to remediate the problem so that it does not return.

I think everyone agrees the S520 is the manual that this industry follows and knowledge of the S500 is required to fully understand it.  Which means you must have a WRT and AMRT for an understanding of industry standard.  These certifications touch on building science however everyone knows full home or building inspection training is required to fully understand systems, structures and building maintenance and failures that can lead to I.A.Q. problems. There are many environmental certifications but the one that seems to be the most rounded is the CIE. 

No one should inspect, test and make recommendations on a home or building without having all four of these trainings:  WRT, AMRT, CIE and Home and Building Inspection Certifications. 

The debate about one or two companies having to provide these services is preposterous.  One company needs to manage the inspection, scope of work and implementation of that scope of work for a project to run smoothly and be affordable.   Consumers can have independent companies provide clearance when necessary. Forcing two companies to run a single project  is ridiculous.   

Certifications for Remediation Should Include The Above as well for supervisors.   Workers should know how to protect themselves and any certification comperable to a CMP or CMT is adequate for a worker.  Companies should be properly insured and there should be regulations protecting consumers from mold during real estate transactions. 

There is your regulation.  Its not complicated. Anything more or less will create industry problems. Good Luck.