How do I set the owner of the Radicale calendar log file when served through Apache2

Question

This is probably a real newbie question, but I've searched and I don't really understand what I'm reading. I've set up a site in Apache2 and it's serving Radicale using WSGI. It all comes to a screaming halt in the logging. Apache2 reports that it doesn't have permission to write to /var/www/radicale/radicale.log, and when I look at it, the file is there but it's 0 bytes long and owned by used by Radicale. I'm guessing the problem is in my site file, but I'm going round in circles. Here is my site file:

ServerName myserver.domain.org

WSGIDaemonProcess radicale user=www-data group=www-data threads=1
WSGIProcessGroup radicale
WSGIScriptAlias / /var/www/radicale.wsgi

<Directory /var/www/intranet/calendars>
    WSGIApplicationGroup %{GLOBAL}
    AllowOverride None
    Order allow,deny
    allow from all
</Directory>

<Location /cal>
    AuthType basic
    AuthName "My Calendar"
    AuthBasicProvider file
    AuthUserFile /etc/radicale/radpasswd
    Require user olivers
</Location>
SSLEngine on
SSLCertificateFile  /etc/ssl/certs/harrison7sprcert.pem
SSLCertificateKeyFile   /etc/ssl/private/harrison7sprkey.pem