LEWISTON — After the tragic drowning of Lewiston Middle School student Rayan Issa during a recent school field trip, Superintendent Bill Webster has presented a directive on school field trips that takes effect immediately. “No parent should have to lose a child,” Webster told the School Committee on Monday night. “And unfortunately, we’ve learned a lot and are learning more on what we should and should not be doing on field trip procedure.” Webster said the directive needs to go into effect right away, because the School Department’s summer learning programs start July 2. “Ultimately, I fully expect that the School Committee will adopt, by fall, a new field trip policy that will replace this directive,” he said. He said the directive is a place to start and it will be updated pending feedback from the community and recommendations from the school’s law firm, Brann & Isaacson. The firm is in the middle of an extensive investigation into Issa’s death June 12 at Range Pond State Park in Poland.