Most notably, the continued improvement in our end markets and the value creation potential of our environmental services businesses that represent about 80% of our revenue.
Third, increasing the enterprise value of our rail business through further operational improvements and backlog growth; and fourth, reducing our financial leverage to a level much closer to our target of about 2.5 times.
We anticipate incremental benefits of about $20 million this year, also or about double those realized in 2020.
We still expect total benefits of $40 million to $50 million by the end of 2022 on a run rate basis.
Although external integration costs are behind us, we will incur about $10 million of cost this year for branding and IT initiatives that will not repeat in 2022.
In Harsco Environmental, it's terrific to have following seas after 18 months of medicine head seas.
Nonetheless, the growth and cash flow trends in the business are favorable, and we are targeting free cash flow generation of 8% to 9% of revenue in 2022 on a path to 10-plus percent in future years.
Harsco's revenues totaled $508 million and adjusted EBITDA totaled $62 million in the fourth quarter.
Our revenues increased 27% over the prior year quarter, with ESOL contributing most of the growth followed by revenue increases within both our Environmental and Rail segments.
Our fourth quarter adjusted EBITDA of $62 million was near the high end of our previously disclosed guidance range.
Harsco's adjusted earnings per share from continuing operations for the fourth quarter was $0.12, this adjusted figure excluded costs for the ESOL integration and the severance costs related to additional restructuring actions in environmental.
Lastly, our free cash outflow was $8 million in the fourth quarter.
Revenues totaled $246 million and adjusted EBITDA was $52 million, representing a margin of 21%.
This EBITDA figure of $52 million compared to $51 million in the prior year quarter and $40 million in the third quarter of 2020.
The LST or steel production volume increase from the third quarter was strong, more than 10% sequentially.
I would also emphasize that the industry continues to operate well below its normal utilization rates, which for our customers, averaged just over 75% in Q4.
Lastly, Harsco Environmental's free cash flow totaled $5 million in the quarter and totaled $69 million for the year.
This full year figure compares with free cash flow of $13 million in the prior year, with the improvement during 2020 driven by lower capex and cash generated from working capital.
For the quarter, revenues were $185 million, and adjusted EBITDA totaled $16 million.
Relative to the third quarter of 2020, revenues were approximately 5% lower, and adjusted EBITDA declined to $16 million.
The segment's free cash flow totaled $17 million in the quarter and for the year, it totaled $55 million versus adjusted EBITDA of $58 million.
ESOL contributed approximately $20 million of EBITDA in the second half of the year, which represents a meaningful improvement year-on-year.
The benefits realized from synergy or improvement initiatives now total approximately $10 million, with the largest improvements coming from disposal optimization and commercial levers.
Rail revenues reached $77 million while the segment's adjusted EBITDA totaled approximately $2.5 million in the fourth quarter.
This EBITDA figure compares with a loss of $2 million in the prior year quarter.
Lastly, let me highlight that our rail backlog remains healthy at just over $440 million, representing a slight decrease from the prior quarter as we continued production under our long-term contracts.
For the full year, revenues increased to $1.9 billion, and adjusted EBITDA totaled $238 million.
Also, our free cash flow was $2 million.
From a financial point of view, we trimmed the capital spending by roughly $65 million and pushed out project spending.
We also took actions to reduce our cost structure by more than $20 million with some of these being permanent savings, as I mentioned earlier.
We ended the year with net debt of $1.2 billion, a leverage ratio of 4.6 times and liquidity of more than $300 million.
Starting with Harsco Environmental, revenue is projected to increase 10% to 15%.
Adjusted EBITDA is projected to increase approximately 20% at the guidance's midpoint.
Next, for Clean Earth, we are guiding to adjusted EBITDA of $72 million to $78 million for the year on revenues of approximately $790 million.
We anticipate that CE's pro forma revenue growth will be within a range of 3% to 5%, while we expect double-digit pro forma EBITDA growth for the business.
We expect to realize an uplift of roughly $20 million from our actions taken to date and those contemplated in 2021.
And it's important to note, a portion of these expenses, approximately $6 million to $8 million, comprising largely duplicative costs for IT integration and branding will not recur in 2022.
We've also allocated an additional $3 million of corporate costs to Clean Earth.
This allocation and the nonrecurring expenditures will total approximately $10 million for the year.
Lastly, for Rail, we project top line growth of 15% to 20% and adjusted EBITDA growth of 25% at the guidance's midpoint.
And lastly, corporate costs are anticipated to be within a range of $33 million to $34 million.
Our adjusted EBITDA is expected to increase to within a range of $275 million to $295 million.
This guidance translates to adjusted earnings per share of $0.59 to $0.76.
The earnings per share range contemplates interest expense of $63 million to $66 million and an assumed effective tax rate of 36% to 38%.
Lastly, we are targeting free cash flow before growth capital spending of $100 million.
And after considering all capex, our full year free cash flow should range from $30 million to $50 million.
This forecast anticipates net capital spending will be within a range of $155 million to $175 million.
And this amount compares with net capex of $114 million in 2020, with most of the increase attributable to growth and renewal expenditures in environmental that were deferred in 2020.
Also note that our projected free cash flow ranges include cash payment deferrals from 2020, including those related to the CARES act of roughly $12 million to $15 million.
We expect to see consolidated run rate free cash flow generation in excess of 6% to 8% of revenue by the end of 2022.
Q1 adjusted EBITDA is expected to range from $52 million to $58 million.

Summary:
Harsco's revenues totaled $508 million and adjusted EBITDA totaled $62 million in the fourth quarter.
Harsco's adjusted earnings per share from continuing operations for the fourth quarter was $0.12, this adjusted figure excluded costs for the ESOL integration and the severance costs related to additional restructuring actions in environmental.
Our adjusted EBITDA is expected to increase to within a range of $275 million to $295 million.
This guidance translates to adjusted earnings per share of $0.59 to $0.76.
And after considering all capex, our full year free cash flow should range from $30 million to $50 million.