BACKGROUND


Models, which relate waste imputs to water quality in the receiving water body, can be employed to evaluate alternative engineering plans for the control and management of water quality. Alternatives such as varying degrees of treatment, relocation of waste discharge points, low flow augmentation, regional treatment systems versus multiple plants, are some of the specific alternatives whose influence on receiving water quality can be assessed by the application of water quality models. The models can also assist in evaluating the relative water quality benefit of the removal of different pollution constituents.

CEPIS/PAHO ACTIONS

The Pan American Center for Sanitary Engineering and Environmental Sciences (CEPIS, Spanish acronym), a specialized agency of the Pan American Health Organization (PAHO), through its Division of Health and Environment (HEP), has developed and applied water quality mathematical models.

 

• RIOS 4.0 (d). Steady-state one dimensional water quality mathematical model for dissolved oxygen, carbonaceous and nitrogenous BOD, coliforms and simplified analyses of conservative and non-conservative substances in rivers. Anaerobic conditions can be analyzed. The model is user-friendly with graphic capabilities. Developed by CEPIS (1995).

• MULTI-SMP. Steady-state one dimensional water quality mathematical model for dissolved oxygen, carbonaceous and nitrogenous BOD and ammonia toxicity in rivers. The model is user-friendly with graphic capabilities. Developed by LTI, Limno-Tech., Inc. (1992) for the EPA.

• SPAM. Finite difference multidimensional steady-state water quality mathematical model for dissolved oxygen, carbonaceous and nitrogenous BOD, coliforms and simplified analyses of conservative and non-conservative substances in surface waters. Developed by Hydroqual (1984), Mahwah, N.J., USA.

• WASTOX. Time variable multidimensional water quality mathematical model for the evaluation of toxic substances in surface waters. Developed by Manhattan College(1994), New York, N.Y., USA, for the EPA.

• LACAT. Simplified water quality mathematical model for the evaluation of trophic states and the management of macro-nutrients in warm water tropical lakes/reservoirs. The model is user-friendly. Developed by CEPIS (1990).

• CLARK. Mathematical model for the calculation of tributary nutrient loadings to lakes based on tributary field data. The model is user-friendly. Developed by Sonzogny, W.C. et al. (1978). Great Lakes Tributary Loadings, EPA and U.S. Task D. Committee.

COUNTRY APPLICATION

The following agencies have utilized water quality mathematical models as planning tools with the technical assistance of CEPIS:

Argentina:

-- Centro de Tecnología del Uso del Agua/Instituto Nacional de Ciencia y Técnica Hídricas (CTUA/INCYTH).

Brazil:

-- Companhia de Tecnologia de Saneamento Ambiental de Sao Paulo (CETESB)

-- Companhia de Agua e Esgotos de Brasília (CAESB)

-- Departamento Municipal de Agua e Esgoto de Puerto Alegre (DMAE)

-- Fundação Estadual de Engenharia do Meio Ambiente de Rio de Janeiro (FEEMA).

Bolivia:

-- Asociación Nacional de Empresas de Servicios de Agua Potable y Alcantarillado (ANESAPA).

Colombia:

-- Corporación Autónoma Regional de las Cuencas de los Ríos Bogotá, Ubaté y Suárez (CAR).

-- Corporación Autónoma Regional del Cauca (CVC).

-- Instituto Nacional de Recursos Naturales (INDERENA).

Costa Rica:

-- Ministerio de Salud.

Cuba:

-- Instituto de Investigaciones del Transporte (IIT)

-- Instituto Superior de Ciencias y Tecnología Nucleares.

Dominican Republic:

-- Instituto Nacional de Aguas Potables y Alcantarillados (INAPA).

-- Corporación de Acueductos y Alcantarillados de Santo Domingo (CAASD).

Ecuador:

-- Municipalidad de Quito.

-- Instituto Ecuatoriano de Obras Sanitarias, Quito (IEOS).

-- Centro de Rehabilitación de Manabí (Embalse Poza Honda), Quito (CRM).

Mexico:

- -Secretaría de Desarrollo Urbano y Ecología (SEDUE).

- -Instituto Mexicano de Tecnología del Agua/Secretaría de Agricultura y Recursos Hidráulicos (IMTA/SARH).

Paraguay:

-- Servicio Nacional de Saneamiento Ambiental, Asunción (SENASA).

Perú:

-- Ministerio de Salud.

-- Instituto Veterinario de Investigaciones Tropicales y de Altura, Lima (IVITA).

Puerto Rico:

-- Environmental Quality Board (EQB).

Uruguay:

-- Administración de Obras Sanitarias del Estado (OSE).

Venezuela:

-- Ministerio del Ambiente y de los Recursos Naturales Renovables (MARNR)

-- Dirección de Investigación del Ambiente, Caracas (DIA).

Financial institutions such as the Inter-American Development Bank (IDB) and the World Bank have recognized the importance of water quality mathematical models as planning tools. In projects financed by the banks, water quality mathematical models should be utilized to evaluate the impacts of wastewater treatment plant effluents on the water quality of the receiving water bodies.