Water abundance and velocity structure in S140, rho Oph A, and B335

We present Monte Carlo radiative transfer models for B335, S140, and rho Op hiuchi A that simulate the emission line arising from the 557 GHz 1(10)-->1 (01) ground-state transition of ortho-(H2O)-O-16. These models reproduce th e line profiles with a combination of turbulent and macroscopic motions, an d are consistent with gravitational infall in rho Oph A. We cannot, however , discriminate infall from outflow for S140. Our models are consistent with ortho-H2O abundances relative to H-2 of 2 x 10(-8) and 4.5 x 10(-9) in S14 0 and rho Oph A, respectively, and an upper limit of 4 x 10(-6) (3 sigma) i n B335, assuming the ratio ortho-H-2/para-H-2 = 0.1. We quantify the impact of dust continuum emission on the derived abundances.