The workers are surrounding a hole with a bucket.
They are digging a new sewer line.
Just because the workers are surrounding a hole does not mean they are digging a new sewer line.
exists e1 x1 x2 x3.(n_worker(x1) & Theme(e1,x2) & Actor(e1,x1) & v_surround(e1) & with(x2,x3) & n_bucket(x3) & n_hole(x2))
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_dig(e1) & n_line(x2) & of(x2,x1) & n_sewer(x1) & a_new(s1) & Theme(s1,x2) & n_thing(x1))