James C. Fish, Jr.
President, Chief Executive Officer at Waste Management
All right, thanks, Ed and thank you all for joining us. 2021 was another very successful year at WM. Our strong operational and financial performance continued throughout 2021 delivering full-year results that achieved or exceeded our financial guidance, which we increased from our original expectations twice during the year. We also successfully integrated the Advanced Disposal Operations, generating synergies that have already exceeded our initial expectations with further synergies to come.
During 2021. We focused on driving disciplined organic revenue growth, advancing technology investments focused on customer retention and growth, and cultivating our people-first culture. Execution on these priorities came together to produce record growth in full-year adjusted operating EBITDA and cash from operations. It can't be overstated how impressive it is that we generated more than $5 billion of operating EBITDA in a year like 2021. This robust operating EBITDA translated into all-time high cash from operations of over $4 billion, which allowed us to return a record of $2.3 billion to our shareholders. Contributing to our operating EBITDA was our pricing, where we finished 2021 on a very strong note. As we made steady progress uncovering the cost inflation in our business with excellent core price results across all lines of business.
John will provide more details here, but we had a record core price in both our landfill and residential businesses. Two areas we've been particularly focused on over the last couple of years. Strong core price translated into the best collection and disposal yield that we've seen in more than a decade, another great story about our pricing efforts is that we're still seeing strong volume growth, and improvements in churn in 2021 churn of 8.4% is an all-time low. As 2022 kicks off we're fully focused on recovering inflationary cost increases through our pricing programs and through the aggressive management of our cost structure.
Our revenue management team is hard at work executing on in 2022 pricing plans so that we can recover the inflationary cost pressures in our business and deliver another successful year. In fact, we've recently seen several large customers who have historically been very price-sensitive renew at significant increases. On the cost front, a big part of that management of our cost structure will be to materially improve our labor efficiency through the application of the technology investments we made over the last 18 months. Our expectation is to attrit between 5 and 7000 positions over the next 4 years without replacements as these positions have become difficult to source and we expect that will continue to be the case.
At the same time, we continue to focus on providing the best workplace for our employees and leveraging our asset network for growth. Regarding our 2022 financial outlook, Devina will provide more details, but at a high level, we expect to deliver total company revenue growth of approximately 6% driving operating EBITDA growth of approximately 7% in 2022. It's fair to point out that both our revenue and our operating EBITDA guidance, are at or above the high end of the range as we targeted for the long term at our Investor Day in 2019. We expect margin expansion in the second half of the year with full-year operating EBITDA margins expected to be flat to up 40 basis points compared to 2021.
This sets us up for another year of robust cash generation. The extraordinary cash generation of our business positions us to plan a 13% increase in our 2022 dividend rate while at the same time making substantial increase investments in high return renewable energy and recycling projects. Tara Hemmer was appointed as our Chief Sustainability Officer last summer and she's charting a path to an aggressive long-term growth for our sustainability businesses. In light of our very strong cash generation, we plan to invest approximately $275 million in 2022 to expand our network of renewable natural gas plants with incremental investments in 2023 through 2025 totaling approximately $550 million.
We expect to build 17 RNG plants over the next 4 years, which would grow our RNG generation by 6 times. With conservative dysfunctions these projects are expected to generate operating-- annual operating EBITDA, run-rate operating EBITDA of more than $400 million by 2026, and in today's higher prices that operating EBITDA more than doubles. In recycling business, we expect to invest $275 million in 2022 in Mirth Technology with incremental investments in 2023 through to 2025 totaling approximately $525 million. These investments accelerate our automation of recycling process processing to reduce costs and improve product quality as well as expand our single-stream recycling footprint.
Together these projects are expected to generate annual run rate incremental operating EBITDA of approximately $180 million by 2026, assuming $125 per tonne blended commodity price. These growth projects further WM's sustainability leadership by increasing the renewable energy generated from our landfill network, expanding single-stream recycling capacity, and automating recycling processing to reduce costs and improve product quality. They also are expected to generate excellent returns that are superior to those of solid waste acquisitions. In closing, we delivered a fantastic year 2021 overcoming the challenges the year presented. As we look ahead to 2022. We remain committed to advancing technology investments to differentiate us automating our processes to reduce our cost to serve and leveraging our sustainability platform for growth. Our success would not have been possible without the best employees in the business and I want to thank all 50,000 of our team members for their contributions.
I'll now turn the call over to John to discuss in more detail our operational results.