Oceanographic Studies: Santo Domingo Sanitary Sewer Master Plan

Location: Santo Domingo, Rep├║blica Dominicana

As a part of the Santo Domingo Sanitary Sewer Master Plan Study, Hazen and Sawyer conducted a series of oceanographic studies in the Caribbean Ocean to assess the feasibility of installing several ocean outfalls in the coastal region of Santo Domingo.

Project Outcomes and Benefits

  • Used an oceanographic model to inform final selection of outfall sites and the feasibility design of the future outfalls.
  • Acquired current data (velocity and magnitude) at varying depths and locations utilizing sail and surface drogues.
  • Collected background water quality data at the near shore and far field for each location, including bacteria analysis (Fecal Coliform/E.Coli.) and water quality analysis (Nitrogen,TSS, and Heavy Metals).
  • Depth profile utilizing a CTD meter resulting in salinity and temperature depth profiles at multiple stations along the center line of the proposed outfall locations.

Drogue cluster trackings were conducted at potential outfall sites to measure current velocities, current direction, and spatial dispersion.

Simultaneous surface and sail drogue trackings help provide a better understanding of the relationship between a variety of oceanographic parameters, time, and water depth.

The information attained during the oceanographic field studies will help develop feasible alternatives to improve the level of sanitary sewer service in Santo Domingo through the potential use of ocean outfalls.

Surface drogues aid determining the displacement of water directly influenced by surface currents and help establish a relationship between wind vectors and surface currents.

The collection of background water quality data is essential in the development of an oceanographic model for the simulation of ocean outfall performance. The field program included bacteria (Fecal Coliform/E.Coli.) and water quality analysis (Nitrogen, TSS, and Heavy Metals)

Salinity, depth, and temperature (STD) profile data was collected up to a depth of 25 meters using a YSl Castaway. The acquisition of data at these depths is unprecedented in Santo Domingo.

Once the project has been completed it will provide a road map to improve the level of sanitary sewer service of Santo Domingo to safeguard public health while minimizing environmental impacts. Funding for the study is provided by the Santo Domingo Water and Sewer Corporation (CAASD) and the International Development Bank (IDB).

The process to identify the most environmentally sustainable design for an outfall requires the analyses of site specific ambient quality characteristics including bathymetric studies, benthic studies, sediments, kinetics (currents and depth density stratification), dispersion, wind effects, wave climate and substrates.

Hazen and Sawyer has completed the collection of the data necessary to perform a thorough analysis of the site specific characteristics. The next phase of the study will integrate the acquired oceanographic data with projected wastewater characteristics, evaluated in the master plan study, for input to the CORMIX2 and Visual Plumes modeling software. This will serve to predict effluent plume behavior for all selected sites, water depths, and outfall diffuser designs.

For more information on this project, or to discuss a similar project in your area, contact

Fernando Chiriboga, Latin America Operations Manager, at fchiriboga@hazenandsawyer.com