The U.S. natural gas market is bursting at the seams. So much natural gas is being produced that soon there may be nowhere left to put the country’s swelling surplus. After years of explosive growth, natural gas producers are retrenching. The underground salt caverns, depleted oil fields and aquifers that store natural gas are rapidly filling up after a balmy winter depressed demand for home heating. The glut has benefited businesses and homeowners that use natural gas. But with natural gas prices at a 10-year low - and falling - companies that produce the fuel are becoming victims of their drilling successes. Their stock prices are falling in anticipation of declining profits and scaled-back growth plans. Some of the nation’s biggest natural gas producers, including Chesapeake Energy, ConocoPhillips and Encana Corp., have announced plans to slow down.