Does it need to be Chorley? You could go to Osbaldeston Equestrian Centre which is a couple of miles off the M6 junction 30 and easy to find. Off the M6 turn right onto the A59 and a couple of miles further along, turn left (sign posted). I'm sure if you gave them a ring they'd be happy to let you use the lorry park and let equine passenger stretch legs and have a pick of grass.