This code removes a variable from the URL and returns the string.http://cflib.org/udf/QueryStringDeleteVar

removeURLVar.cfm

<cfscript>
/**
 * Deletes a var from a query string.
 * Idea for multiple args from Michael Stephenson (michael.stephenson@adtran.com)
 * 
 * @param variable      A variable, or a list of variables, to delete from the query string. 
 * @param qs      Query string to modify. Defaults to CGI.QUERY_STRING. 
 * @return Returns a string. 
 * @author Nathan Dintenfass (michael.stephenson@adtran.comnathan@changemedia.com) 
 * @version 1.1, February 24, 2002 
 */
function queryStringDeleteVar(variable){
    //var to hold the final string
    var string = "";
    //vars for use in the loop, so we don't have to evaluate lists and arrays more than once
    var ii = 1;
    var thisVar = "";
    var thisIndex = "";
    var array = "";
    //if there is a second argument, use that as the query string, otherwise default to cgi.query_string
    var qs = cgi.query_string;
    if(arrayLen(arguments) GT 1)
        qs = arguments[2];
    //put the query string into an array for easier looping
    array = listToArray(qs,"&");        
    //now, loop over the array and rebuild the string
    for(ii = 1; ii lte arrayLen(array); ii = ii + 1){
        thisIndex = array[ii];
        thisVar = listFirst(thisIndex,"=");
        //if this is the var, edit it to the value, otherwise, just append
        if(not listFind(variable,thisVar))
            string = listAppend(string,thisIndex,"&");
    }
    //return the string
    return string;
}
</cfscript>

Example:
<div id="containered" class="conteinerListsBox panel-collapse collapse" style="display:none;">
    <a href="##" class="close closeMenu">close</a>
    <ul id="listyles" class="lists">
        <cfloop from="10" to="#attributeOption.recordCount#" index="attributeIndex">
            <li class="selectListItem" id="#attributeOption.ATTRIBUTEVALUE[attributeIndex]#">
                <a href="#productSmartList.buildURL('#filterPrefix##attributePath##attributeCode#=#URLEncodedFormat(attributeOption.attributeOptionValue[attributeIndex])#')#" <cfif productSmartList.isLikeFilterApplied(attributeCode, attributeOption.attributeOptionValue[attributeIndex]) or productSmartList.isFilterApplied(attributeCode, attributeOption.attributeOptionValue[attributeIndex])> class="checked"</cfif> id="object#attributeIndex#"><span class="checkboxImgUnchecked"></span>#attributeOption.attributeOptionLabel[attributeIndex]# ( #attributeOption.prodCount[attributeIndex]# )</a>
            </li>
            <cfif attributeIndex MOD 9 EQ 0>
                </ul><ul id="listyles" class="lists">
            </cfif>
        </cfloop>
    </ul>
</div>