Wall Street wasn't impressed with Emerge Energy Services (NYSE: EMES) second-quarter results: Traders sent the stock down more than 10% on Wednesday after it announced earnings. Not only did the company miss expectations, management indicated that it was seeing a minor slowdown in the frack sand market. Funny thing, though: There aren't many other frack sand suppliers echoing that sentiment.Let's take a look at what happened this past quarter, and why Emerge seems to be hitting a soft spot when others aren't. DATA SOURCE: EMERGE ENERGY SERVICES EARNINGS RELEASE.