How to Become an MCACC Volunteer. Thank you for considering volunteering to support Maricopa County's shelter pets!You are always so respectful and kind to the people we serve. There may be paperwork or reports to fill out. To learn more about volunteering, we suggest you check out the resources and comments below. Or give us a call at 602-888-7037. Thank you for your interest in volunteering for the City of Maricopa. With this application, please attach an up-to-date resume and cover letter about yourself. We believe volunteers are a vital part of our organization and help us to build community. Click the button below to tell us about yourself.