Calgon Carbon 10-K 2012 FY Annual report

Exhibit 23.1

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Directors and Shareholders of

Calgon Carbon Corporation

Pittsburgh, Pennsylvania

We have audited the consolidated financial statements of Calgon Carbon Corporation and subsidiaries (the “Company”) as of December 31, 2012 and 2011, and for each of the three years in the period ended December 31, 2012, and the Company’s internal control over financial reporting as of December 31, 2012, and have issued our reports thereon dated February 27, 2013; such reports are included elsewhere in this Form 10-K.  Our audits also included the consolidated financial statement schedule of the Company listed in Item 15. This consolidated financial statement schedule is the responsibility of the Company’s management. Our responsibility is to express an opinion based on our audits. In our opinion, such consolidated financial statement schedule, when considered in relation to the basic consolidated financial statements taken as a whole, presents fairly, in all material respects, the information set forth therein.

/s/ Deloitte & Touche LLP

Pittsburgh, Pennsylvania

February 27, 2013