Who we are

Yellow Tree is passionate about the environment and about serving others. We are a team of engineers and environmental scientists that specialise in stack emissions testing, and we love our work.

Who we are

Our awesome staff are here to serve.

Caitlin Morris

Caitlin Morris

Environmental Engineer

BSc Chem Eng, LLM in progress

Cait is a superb chemical engineer! She is incredibly bright and her work is flawlessly accurate. Cait has extensive knowledge of the legislation and air pollution abatement. She writes superb reports and helps our clients.

Matthew Mwepu

Matthew Mwepu

Lead Scientist

NDip Mech Eng

Matt is our most experienced stack tester. With a wealth of knowledge spanning the testing of all emissions from particulate matter through to dioxins and furans, Matt is our guy! We love his confidence and bold leadership!

Rumbi Zireva

Rumbi Zireva

Air Quality Consultant

BSc Chem Eng, MSc Med

Rumbi is both incredibly bright and dedicated. As a talented chemical engineer (with a Masters degree) she heads up our consulting department doing AEL applications, carbon tax consulting, and NAEIS submissions, and pursuing our ISO 17025.

Alen Siwela

Alen Siwela

Assistant Scientist

NDip Chem Eng

Alen’s life is characterised by perseverance and his story is inspirational. Having lost his parents at a young age, Alen fought to put himself through higher education. He is bright and has the courage that makes a stack scientist exemplary.

Ray Slinger

Ray Slinger

Operations Manager

BSc Environmental Science

Ray is effervescently joyful. As Operations Manager, he manages Yellow Tree’s three stack testing teams and health & safety. They say that one should lead with the heart of a servant, and serve with the heart of a king. That is Ray!

Bertus Bonthuys

Bertus Bonthuys

General Manager

BSc Mech Eng

Bertus is a great leader! As General Manager he oversees the team, assists key clients, and maintains the high energy environment and client-centric approach that we feel characterises Yellow Tree.

Khumbu Badantswana

Khumbu Badantswana

Lead Scientist

NDip Chem Eng

Khumbu is our genius. He is the first to solve a problem when testing a boiler or process stack. His quietness belies his confidence and his friendliness. We are blessed to have him head up our Johannesburg team.

Monique

Monique

Admin, Health, and Safety

NDip Health and Safety

Monique is passionate about safety and about protecting the people that work at Yellow Tree. She has always protected others and placed the needs of others above her own. She is loyal and kind and we are excited about her future.

Sean Charteris

Sean Charteris

Managing Director

PR Chem Eng

Sean is a professionally registered Chemical Engineer with a wealth of experience in combustion, energy generation and industrial emissions. He is passionate about the environment and loves people.

Sakhumzi Baliso

Sakhumzi Baliso

Lab and QC Manager

NDip Analytical Chemistry

Sakie is one of our best! With years of emissions testing experience, he now oversees our laboratory, our field equipment and adherence to US EPA methods. His smile is contagious and lights up the room!

Sherri Mason

Sherri Mason

Lead Scientist

BSc Mech Eng

Sherri received innumerous accolades when working as the Systems Engineer of the Electrostatic Precipitators and SO3 Plant, at Eskom’s Grootvlei Power Station. She brings maturity, experience and a quiet authority to the Yellow Tree team!

Riyaal Cerpath

Riyaal Cerpath

Lead Scientist

BSc Chem Eng

As a graduate chemical engineer who was head student of his residence, with academic colours from Maritzburg College, Riyaal has a rock solid work ethic and is a considerate and thoughtful leader. Riyaal has a bright future in the field of Air Quality.

Grant Derrick

Grant Derrick

Instrumentation Engineer

NDip Elec Eng

Grant’s never-say-die attitude and can-do ability to solve problems, make him an indispensable asset to the Yellow Tree Team. Grant looks after Yellow Tree’s highly technical air quality and stack sampling equipment.

Ernest Kanyeta

Ernest Kanyeta

Lead Scientist

NDip Chem Eng

At Yellow Tree we want bright engineers who also have grit! Having graduated top of his class at CPUT and overcome many challenges in life, we have found such an individual in Ernest! His enthusiasm can not be extinguished.

NLA Certified

We are certified with the National Laboratory Association of South Africa. This ensures that we are accredited to test your stack emissions. If you would like to learn more, visit the NLA website here.