What happened

Shares of Casella Waste Systems (CWST -0.70%) rose 16.5% in March after the regional trash hauler announced earnings on March 1 that beat its guidance and analysts' expectations. 

The stock also popped on March 22 on no apparent news. In the wake of a mid-month price decline, investors may have been using the opportunity to scoop up shares.

Trash can spilling money.

2016 was a good year for the solid waste industry, with major players like Casella Waste Systems posting significant gains. Image source: Getty Images.

So what

Casella's strong earnings were what propelled its share price higher. The company reported fourth-quarter revenue that was up 2.7% from the year-ago quarter, and annual revenue was up 3.4% over fiscal year 2015.

Adjusted EBITDA was also up 5.9% year over year for the quarter and up 13.7% for the year. 

The company also provided positive guidance for 2017, projecting revenue of between $577 million and $587 million, compared to $565 million in FY 2016. It also predicted adjusted EBITDA of between $124 million and $128 million, compared to $120.6 million in FY 2016, and normalized free cash flow between $32 million and $36 million, compared to $27.1 million in FY 2016.

In a press release, CEO John Casella provided some additional details on what drove the company's growth:

From an operating standpoint, our disciplined solid waste pricing programs continued to outpace internal inflation with overall solid waste pricing up 2.6% in the quarter, driven by strong residential and commercial pricing, which was up 3.6%, and landfill pricing up 2.7%. Further, our efforts to reduce operating costs and drive efficiencies continued to gain traction in the fourth quarter, with our cost of operations as a percentage of revenues down 100 bps year-over-year.

Now what

Casella has been a solid outperformer for the last year, but it's making up for lost ground. As this five-year chart shows, the stock languished from 2012 to 2014 while larger waste haulers Waste Management and Republic Services were experiencing slow and steady growth. All three companies had a stellar 2016:

WM Chart

WM data by YCharts.

Casella clearly intends to keep doing what it's doing, and it seems to be paying off for the company and its investors. Last month's jump is just another sign of that.