Our impressive top line performance driven by strong Event Business and continued operational excellence across all of our facilities produced a second consecutive quarter of record financial results. Operating income grew 25% to a record $15.5 million for the third quarter of 2013 while adjusted EBITDA increased 20% to a record $20.1 million. Total revenue for the third quarter of 2013 increased 16% to $53.1 million on a 10% increase in treatment and disposal ("T&D") revenue. Year to date, total revenue is up 19% to $141.8 million on T&D revenue growth of 13%. Strength in the commercial business sector has more than offset the expected softness in our government business. We also saw significant expansion in our T&D gross margin due to continued operational improvements across our facilities as well as service mix. Year to date, earnings per share increased to $1.24 and, after excluding foreign currency translation gains and losses and business development expenses, we reported adjusted EPS of $1.29 for the first nine months of 2013, up 24%.
Growth in our Event Business in the second half of the year is being driven by a combination of solid new project demand and accelerated shipments on longer-term projects. Our underlying Base Business is performing as expected and demand for our thermal recycling services remains strong. With a solid fourth quarter outlook and a healthy pipeline that runs into 2014, we now expect full year earnings for 2013 to range from $1.68 to $1.73 per diluted share, up from our previous range of $1.45 to $1.55 per share. Adjusted EBITDA is expected to range from $67 million to $69 million, up from our previous guidance of $62 million to $65 million. This continues to exclude the impact of foreign currency translation gains or losses and business development expenses.
In closing, we are excited to continue our momentum into the fourth quarter and expect 2013 to be another record year for US Ecology. We believe we have best-in-class assets and permits and the premier sales team in the industry to continue to target and win business to generate growth in 2014 and beyond. With our industry leading return on invested capital, we remain committed to reinvesting in our business and in complementary businesses to broaden our service offerings, grow revenue and earnings and deliver sustainable, long-term shareholder value.
President and Chief Executive Officer