Industrial production in the United States was flat in July, Federal Reserve data showed Thursday, in a fresh sign that economic growth remains tepid. Manufacturing production fell 0.1 percent, and utility production fell 2.1 percent, offset by a 2.1 gain in output in the mining sector. Total industrial production in July was a small 1.4 percent above the year-earlier level, and still 11 percentage points lower than the average in 2007, before the US economy plunged into recession.