**Exhibit 31.2**

**Certification pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section302 of the Sarbanes-Oxley Act of 2002.**

**CERTIFICATION**

I, Leroy M. Ball, certify that:

1.  I have reviewed this quarterly report on Form 10-Q of Calgon CarbonCorporation.

2.  Based on my knowledge, this report does not contain any untruestatement of a material fact or omit to state a material fact necessary to makethe statements made, in light of the circumstances under which such statementswere made, not misleading with respect to the period covered by thisreport;

3.  Based on my knowledge, the financial statements, and other financialinformation included in this report, fairly present in all material respects thefinancial condition, results of operations and cash flows of the registrant asof, and for, the periods presented in this report;

4.  The registrant’s other certifying officer(s) and I are responsiblefor establishing and maintaining disclosure controls and procedures (as definedin Exchange Act Rules 13a-15e and 15d-15e) and internal control over financialreporting (as defined in Exchange Act Rules 13a-15f and 15d-15f) for theregistrant and we have:

(a) designed such disclosure controls and procedures, or caused such disclosurecontrols and procedures to be designed under our supervision, to ensure thatmaterial information relating to the registrant, including its consolidatedsubsidiaries, is made known to us by others within those entities, particularlyduring the period in which this report is being prepared;

(b) designed such internal control over financial reporting, or caused suchinternal control over financial reporting to be designed under our supervision,to provide reasonable assurance regarding the reliability of financial reportingand the preparation of financial statements for external purposes in accordancewith generally accepted accounting principles;

(c) evaluated the effectiveness of the registrant’s disclosure controls andprocedures and presented in this report our conclusions about the effectivenessof the disclosure controls and procedures, as of the end of the period coveredby this report based on such evaluation; and

(d) disclosed in this report any change in the registrant’s internalcontrol over financial reporting that occurred during the registrant’s mostrecent fiscal quarter (the registrant’s fourth fiscal quarter in the caseof an annual report) that has materially affected, or is reasonably likely tomaterially affect, the registrant’s internal control over financialreporting; and

5.  The registrant’s other certifying officer(s) and I have disclosed,based on our most recent evaluation of internal control over financialreporting, to the registrant’s auditors and the audit committee ofregistrant’s board of directors (or persons performing the equivalentfunctions): 

(a) all significant deficiencies and material weaknesses in the design oroperation of internal control over financial reporting which are reasonablylikely to adversely affect the registrant’s ability to record, process,summarize and report financial information; and

(b) any fraud, whether or not material, that involves management or otheremployees who have a significant role in the registrant’s internal controlover financial reporting.

Date:  December 13, 2006

|   | /s/ Leroy M.   Ball     |   |
|--------|-------------------------|--------|
|   |                         |   |
| Name:  | Leroy M. Ball           |   |
| Title: | Chief Financial Officer |   |