Jon Vander Ark
President and Chief Executive Officer at Republic Services
Thanks, Aaron. Good afternoon, everyone, and thank you for joining us. Our second quarter results continue to demonstrate the value created by our differentiated capabilities and ability to harness the positive momentum in our business.
We delivered outsized revenue growth, both organically and through acquisitions, while generating underlying margin expansion. This was achieved by pricing in excess of our internal cost inflation and continued savings from productivity initiatives. The fundamentals in our business remain strong, and we remain well positioned to capitalize on additional growth opportunities in the marketplace.
During the second quarter, we delivered revenue growth of 21%, generated adjusting [Phonetic] earnings per share of $1.32, which is a 21% increase over the prior year, and produced more than $1.1 billion of adjusted free cash flow on a year-to-date basis, which is a 14% increase over the prior year.
We continue to effectively allocate capital by investing in value-creating acquisitions and returning cash to our shareholders. Year-to-date, we invested $2.5 billion in acquisitions, which includes the acquisition of US Ecology. The integration of US Ecology is well underway and progressing as planned. We are encouraged by early cross-selling results and remain confident that we will achieve at least $40 million of cost synergies.
We have one of our most robust acquisition pipelines ever with opportunities to close transactions this year and into 2023. We now expect to invest over $600 million in acquisitions, apart from US Ecology for the year. Substantially all of these deals are in the recycling and solid waste space. Year-to-date, we've returned $495 million to our shareholders through dividends and share repurchases. Additionally, we recently announced an increase to the dividend for the 19th consecutive year.
During the second quarter, we reported organic volume growth of 2.4%, which was broad-based across geographies and market verticals. Simultaneously, we demonstrated our ability to price. Core price reached an all-time high of 6.2% and average yield increased to 5%. This is the highest level of pricing in company history. At the same time, we are experiencing higher-than-expected inflationary pressures that continue to persist.
That said, we expect to continue to price more than our internal cost inflation, ultimately leading to full year results that are projected to exceed original expectations. We now expect adjusted EPS in a range of $4.77 to $4.80 and adjusted free cash flow in a range of $1.7 billion to $1.725 billion. This represents an increase of approximately 4% from the midpoint of the prior guidance.
Finally, we believe creating a more sustainable world is both our responsibility and a platform for growth. We recently published our latest Sustainability Report, highlighting the progress we are making toward our most significant opportunities to positively impact key stakeholders and the environment. We reported a 9% decrease in greenhouse gas emissions from our 2017 baseline, which keeps us well positioned to achieve our interim target of a 10% reduction by 2025.
We also highlight progress made on climate leadership goals, including circular economy and renewable energy. These goals are supported by investments we are making in polymer centers and landfill gas projects, which are progressing as planned. In addition to having a positive impact on the environment, these innovative solutions are a platform for growth.
Our efforts continue to be recognized externally as Republic was recently named to 3BL Media's 100 Best Corporate Citizens list for the third consecutive year.
I'll now turn the call over to Brian, who'll provide details on the quarter.