Evaluation of mixing zone models: CORMIX, PLUMES and OMZA with field data from two Florida ocean outfalls

This paper presents an evaluation of three mixing zone models: CORMIX, PLUMES, and OMZA using field data from two Florida ocean outfalls: Hollywood and Miami-Central outfalls. The Hollywood outfall has a single port outlet and the Miami-Central outfall has a multiport diffuser. Both outfalls discharge secondary effluent. For the nearfield, all of the three models predict realistic initial dilutions for the tests at the Hollywood outfall. The three models predict realistic initial dilutions too for the tests at the Miami-Central outfall except three cases in CORMIX predictions and two cases in PLUMES predictions (out of 20 cases). For the nearfield and farfield combined, CORMIX significantly overestimates dye concentrations for the tests at the Hollywood outfall but underestimates dye concentrations within the 300 m to 400 m range for the tests at the Miami-Central outfall. PLUMES predictions agree reasonably well with the field data for the range from 300 m to 800 m but do not agree well within the 300 m range for the tests at both outfalls. OMZA predictions agree well with the field data within the 800 m range for the tests at both outfalls.