Waste removal companies such as Waste Management (WM), Republic Services (RSG) and Stericycle (SRCL) are feeling the sting of high fuel prices, but investors shouldn't trash these companies by any means. Demand for their services is inelastic: Good times or bad, someone has to haul away the garbage.

Take Waste Management. Revenues for the fourth quarter of 2011 hit $3.41 billion, up 7 percent on year. Net income for the fourth quarter came to $266 million, down 5 percent on year thanks to one-time costs related to past acquisitions and legal affairs.

"We had a very good fourth quarter. Our core collection, landfill, and transfer station businesses performed well," company CEO David P. Steiner says in an earnings statement.

Revenues at Stericycle, which focuses a good deal on handling medical waste, hit $446.6 million for the fourth quarter of 2011, up 13.5 percent from the same period a year earlier. Net income attributable to Stericycle for the fourth quarter of 2011 hit $64.3 million, up 28 percent on year.

Republic Services meanwhile reported $2 billion in fourth quarter revenue last year, unchanged from a year before and mainly due to expiring contracts, while net income was up 29 percent at $191 million.

Demand is solid

The demand for waste removal is there. If companies control costs, business will go well, experts say.

Standard & Poor's says the sector is a stable one in that it's a largely recession-proof, albeit not high-growth, industry.

"Demand and prices for both solid and hazardous waste disposal should hold up reasonably well, though we don't expect any meaningful increases in either — and we believe companies have sufficient liquidity after they refinanced their debt maturities over the past few years," Standard & Poor's credit analyst James Siahaan says in a report on the sector.

"We also expect most companies to have enough financial flexibility to absorb higher fuel costs, if necessary, while engaging in share buybacks and mergers and acquisitions (M&A)."

Waste Management in particular is growing via M&A. The company last February acquired Reliable Environmental Transport for an undisclosed sum.

Reliable Environmental Transport caters to the booming natural gas exploration and production industry, moving both hazardous and non-hazardous waste.

Waste Management will release first quarter results on May 17.