Jon Vander Ark
President and Chief Executive Officer at Republic Services
Thanks, Aaron. Good afternoon, everyone, and thank you for joining us.
Our strong second quarter results demonstrate the value created by our differentiated capabilities and the execution of our strategic priorities. We continue to successfully grow our business, both organically and through acquisitions, while enhancing profitability.
During the quarter, we delivered revenue growth of 9%, including more than 4% from acquisitions; generated adjusted EBITDA growth of 10.5%; expanded EBITDA margin by 40 basis points; reported adjusted earnings per share of $1.41; and produced $1.26 billion of adjusted free cash flow on a year-to-date basis, a 10% increase over the prior year.
We continue to effectively allocate capital by investing in acquisitions to create long-term value. Year-to-date, we invested $927 million of acquisitions. All transactions were in the recycling and solid waste space, including the acquisition of assets in Colorado and New Mexico from GFL. The M&A environment remains active with opportunities in both recycling and solid waste and environmental solutions businesses. We now expect investment in value-creating acquisitions to exceed $1 billion for the year.
We are making great progress on the integration of US Ecology and increasing the profitability of our Environmental Solutions business. Pricing realization in this business remained strong. Customers value our complete set of products and services. We have achieved over $110 million in new sales to date as a result of cross-selling our products and services. The sales pipeline is robust with opportunities for organic growth and expansion of services within our existing customer base. We achieved more than $40 million of annualized cost synergies and EBITDA margin in the Environmental Solutions business improved more -- to more than 22% in the quarter.
The strong results we achieved in the first half of the year, along with the positive momentum in our business, supports a full year financial outlook that exceeds our original expectations. We now expect revenue in a range of $14.775 billion to $14.85 billion, adjusted EBITDA in a range of $4.34 billion to $4.36 billion, adjusted earnings per share in a range of $5.33 to $5.38, and adjusted free cash flow in a range of $1.9 billion to $1.925 billion. Our updated financial guidance includes the contribution from acquisitions closed through June 30.
The results we are delivering are made possible by executing our strategy, supported by our differentiated capabilities, customer zeal, digital, and sustainability.
Regarding customer zeal, our efforts to deliver industry-leading service continues to drive sustained customer loyalty and organic growth. Our customer retention rate remained over 94%, and we continue to see positive trends in our Net Promoter Score, supported by improved service delivery. Organic revenue growth remained strong during the quarter and, simultaneously, increases in both price and volume. Core price on related revenue was 8.8% and average yield on related revenue was 7.1%. This includes landfill MSW yield of 6.2%. This is the highest level of performance in company history in this category. Organic volume growth on related revenue was 50 basis points.
Turning to digital, we have reached a milestone in our efforts to create digital tools to enhance our customers' and employees' experience and deliver meaningful financial benefits. The deployment of RISE tablets in our recycling and solid waste collection business was completed during the second quarter. The next phase of our digital operations is expected to drive additional productivity savings through route adherence, improved safety performance and provide more predictable service delivery for our customers. In total, we believe the benefits of our digital initiatives are worth approximately $100 million, with $50 million already achieved and $50 million to be captured over the next three years.
Moving on to sustainability. We continue to invest in differentiating capabilities to leverage sustainability as a platform for profitable growth. Earlier today, we announced a joint venture with Ravago called Blue Polymers. This groundbreaking partnership further supports our efforts to lead in plastic circularity. Blue Polymers will utilize recycled olefins from our polymer centers to create blended pellets for use in manufacturing sustainable packaging. We expect to open four facilities beginning in late 2024, with earning contribution beginning in 2026. Development of our polymer centers in Las Vegas and the Midwest remain on track, with the centers becoming operational in late '23 and late '24, respectively.
Demand for recycled plastics remains strong as the consumer goods industry continues to work toward achieving their sustainability goals. For example, we are partnering with The Coca-Cola Company to supply recycled PET from our polymer centers for use in sustainable packaging. The 57 renewable natural gas projects being co-developed with our partners are advancing. We expect four of these projects to be operational by the end of the third quarter.
Finally, we continue to believe that creating a more sustainable world is our responsibility and a platform for growth. We recently published our latest Sustainability Report, highlighting the progress we are making on our 2030 goals. These goals are supported by investments we are making in polymer centers, the Blue Polymers joint venture, renewable natural gas projects and fleet electrification.
I will now turn the call over to Brian, who will provide details for the quarter.