Option Name:cache_effective_group
Default Value:none
Suggested Config:

	If you want Squid to run with a specific GID regardless of
	the group memberships of the effective user then set this
	to the group (or GID) you want Squid to run as. When set
	all other group privileges of the effective user is ignored
	and only this GID is effective. If Squid is not started as
	root the user starting Squid must be member of the specified