SQL Error: Unknown column 'sc.text' in 'where clause' (1054)

Query:
SELECT COUNT(*) FROM loads l, routes r, load_offers w WHERE l.id = w.lid AND r.id = w.rid AND (sc.text LIKE '%r_district%')
Context:/var/www/virdru/data/www/vird.ru/Library/Handler/CargoHandler.php line 589