memory leak issues using schematron 5.* libraries

Question

I have a memory leak problem while using schematron libraries. here is the method

public int validateSchematron(File schemaFile1, File inputFile1, StringBuilder serviceReturnStatus) {

    File schemaFile = schemaFile1;
    File inputFile = inputFile1;

    try {

        IReadableResource schFile = new FileSystemResource(schemaFile);
        ISchematronResource aResSCH = new SchematronResourceSCH(schFile);

        if (!aResSCH.isValidSchematron ()) {
            serviceReturnStatus.append("\nInvalid Schematron file:" + schemaFile.getName());
            return STEP_STATUS_FAILRE_INT;
        }

        int count = 0;
        Source xmlFile = new StreamSource(inputFile);
        SchematronOutputType schematronOutputType = aResSCH.applySchematronValidationToSVRL (xmlFile);
        List<Object> failedAsserts = schematronOutputType.getActivePatternAndFiredRuleAndFailedAssert();
        if(failedAsserts != null) {
            for (Object object : failedAsserts) {
                if (object instanceof FailedAssert) {
                    if (!(count > 0)) {
                        serviceReturnStatus.append("\n\nSchematron (" + schemaFile.getName() + ") validation errors encountered:");
                    }
                    final FailedAssert failedAssert = (FailedAssert) object;
                    if ((failedAssert.getFlag().equalsIgnoreCase("warning"))) {
                        if (treatWarningAsError)
                            validationFailure = true;
                        serviceReturnStatus.append("\n" + failedAssert.getFlag().toUpperCase() + " : ");
                        serviceReturnStatus.append(failedAssert.getText());
                        serviceReturnStatus.append("\n\t" + "Location : " + failedAssert.getLocation());
                    }
                    if ((failedAssert.getFlag().equalsIgnoreCase("error"))) {
                        validationFailure = true;
                        serviceReturnStatus.append("\n" + failedAssert.getFlag().toUpperCase() + " : ");
                        serviceReturnStatus.append(failedAssert.getText());
                        serviceReturnStatus.append("\n\t" + "Location : " + failedAssert.getLocation());
                    }
                    if ((failedAssert.getFlag().equalsIgnoreCase("fatal"))) {
                        validationFailure = true;
                        serviceReturnStatus.append("\n" + failedAssert.getFlag().toUpperCase() + " : ");
                        serviceReturnStatus.append(failedAssert.getText());
                        serviceReturnStatus.append("\n\t" + "Location : " + failedAssert.getLocation());
                    }
                    count++;
                }
            }
        }
                }
    catch(IllegalArgumentException ia) {
        serviceReturnStatus.append("\n\nInvalid or malformed input file.\nPlease retry or correct the input file.\n\n" + ia.getLocalizedMessage());
        validationFailure = true;
    }
    catch(Exception e){
        serviceReturnStatus.append("\n\n" + e.getLocalizedMessage());
        validationFailure = true;
        return STEP_STATUS_FAILRE_INT;
    }

    return STEP_STATUS_SUCCESS_INT;
}

The problem appears to be when the schematron file is validated DOM objects are created that persist after the method returns. Any ideas or suggestions on why that would be?