PORTLAND — The Zone Urban Epic Triathlon is set to happen this weekend, with an all-day festival afterwards.

The waterfront triathlon, now in its third year, begins at 8:30 a.m. at East End Beach, were participants will – if enterococcus levels aren’t too high – jump in for a half-mile out-and-back swim.

The East End Beach has been closed to swimming or under advisory for the past week due to the amount of rain. Enterococcus is an indicator organism for measuring fecal contamination at beaches.

If the triathletes can’t go in the water July 18, the event turns into a duathlon. From the beach, competitors will run half a mile up the Eastern Promenade Trail to Portland Yacht Services, where they’ll hop on bikes to pedal a 13-mile course around the Eastern Prom, out to Baxter Boulevard and back to Portland Yacht Services. A 3.7-mile run along the Eastern Prom and back to the Maine State Pier wraps up the race.

About 350 participants are expected for the event, and there are several road closures Saturday morning, including Baxter Boulevard from 6:30 a.m. to 10:30 a.m. Other closures are from 8:30 a.m. to 10:30 a.m. and include:

•  Fore Street from Mountfort to Morning.

•  Franklin Arterial northbound, from Cumberland Avenue to Marginal Way

•  Marginal Way westbound, from Franklin to Preble Street Extension.

•  Preble Street, Back Cove side, from Marginal to Baxter Boulevard

•  Washington Avenue from Madison Street to Baxter Boulevard

•  Interstate 295 Exit 8, southbound.

•  I-295 Exit 7, southbound and northbound.

There is also an Urban Epic kids race presented by Big Brothers Big Sisters of Southern Maine, which will benefit from the event. Kids 7 to 13 years old will compete in a swim/run race, while smaller children can enter a 200-yard dash., while

There is a post-event party at the Maine State Pier, with a Smuttynose Beer Garden, Mammut climbing wall, food vendors and music by the Jason Spooner Trio. The party is free and open to the public.

For more information, go to urban-epic.com and select the Portland race link.

Kate Bucklin can be reached at 781-3661 ext. 106 or kbucklin@theforecaster.net