The best alternative for the treatment of wastewater in coastal villages.

Installing outfall Carupano – Venezuela

Outfalls with large dilution capacity combined with removal treatment solids (primary treatment) are the most efficient, reliable and economical to manage domestic wastewater in nearby sea populations alternative over any secondary treatment is conducted in treatment plants.

Henry J. Salas, adviser Control of Water Pollution CEPIS, in its study called “EMISSARIES ALTERNATIVE SUBS VIABLE FOR DISPOSAL OF SEWAGE IN COASTAL CITIES IN LATIN AMERICA AND THE CARIBBEAN” said that since the beginning of humanity, world’s oceans, which cover 70% of the surface of the earth, have been used as a receptacle of human waste, however, generally have not undergone major changes since the chemical composition of the sea has remained essentially the same for more than a million years.

Furthermore, when the huge amount of organic matter and sediment carried to the sea by rivers in the world as a result of natural processes, the contribution of wastewater produced by man is small compared. An interesting observation about the relative unimportance of organic matter was made by Dr. John D. Isaacs, who noted that only the fecal discharge anchovies coastal waters of southern California was equivalent in organic content (biological demand oxygen and suspended solids) to the waste water of about 90 million people, and this is just one of the hundreds of species of marine life.

Henry J. Salas also said that the real problems of pollution occur when man concentrated waste in restricted rather than disperse them in broader areas where natural purification process can operate more easily areas. Typically, large population centers developed along the coasts; in view of the magnitude of the ocean, it is logical and economic, that the discharge of sewage from coastal cities is made to adjacent marine waters. A properly designed outfall provides an effective treatment of these wastewater mechanism. It can be achieved initial immediate dilutions of the order of 100 to 1 consistently in the first few minutes of download, reducing the concentration of organic matter and nutrients, characteristics of domestic wastewater to levels that would not have ecological effects adverse in the open sea. On the contrary, the introduction of such substances usually faulty nutrient ocean environment could be beneficial in many situations.

(*)

Fundamental variables in the design of a outfall.

Difusor_submarino_colocado_en_lecho_marino.

Submarine discharge diffuser

Dilution capacity of an emissary constitute three main factors:

a).-Distance wing that the effluent is discharged from the coast or to areas of human uses,

b).-Depth of discharge of effluent, and

c).-The efficient design of the diffuser discharge which must be adapted to the specific conditions of the marine area that will receive the effluent.

A illustrative and using approximate figures way, an outfall should be able to ward off the effluent at distances between 2 to 5 Km and possibly reach above 15 m deep (depending on the flow of the effluent, the morphology of the coast and the bathymetric profile of the discharge area), in order to ensure excellent dilutability changing oceanographic conditions that provide the different seasons. It should be noted that these two variables, distance and depth, are complementary, allowing to achieve excellent results with different combinations between them, finding for example be necessary to increase the distance from the outfall when conditions do not allow find great depths and otherwise too, to coast with great depths greater elongation of the outfall would be required.

As third factor in improving dilution (in the so-called primary phase) represents the diffuser, also by way of approximation it should provide the greatest number of discharge ports (or nozzles), appropriate depth, the flow of effluent and characteristics of marine currents found in the download area. This gives us a schematic and rough idea of how they play these three factors in the operation of an emissary, but the beginning of each design project should procure some studies that provide the information needed to optimize its smooth operation and construction optimized costs outfall. These studies should primarily see three aspects:

1.-Marine bathymetry and topography of the coastal zone related area: With this information, you can determine potential suitable for the installation of the outfall routes, providing deep sea area under study, and the approximate length.

2.-Study current, waves, tides and winds: With these results, we can understand the behavior of currents in the study area, in magnitude and direction over time. This allows a simulation of dilution with specialized software, placing an unloading area where the prevailing currents for the longest time of the year allow the effluent away from the coast or areas of human uses.

Of these two aspects it is possible to obtain the information necessary for the design of the diffuser, with which pretend to achieve the highest possible primary dilution for the rest of the work is achieved with the action of ocean currents.

3.-Composition of the seabed: This study seeks to examine in detail the composition of the sea, geologically bed (if rocky, sandy, muddy, clay, etc.) and biologically (as ecosystems: coral reefs, sandy areas, grasslands Thalasia, etc). On the one hand it allows us to design the route emissary intervening as little as possible to the most fragile ecosystems such as coral, and moreover it is possible to design the work of burying the pipeline, according to the hardness of the ground, for proper protection of it.

References:

(*) Study: “OUTFALL VIABLE ALTERNATIVE FOR DISPOSAL OF SEWAGE IN COASTAL CITIES IN LATIN AMERICA AND THE CARIBBEAN”. Author: HENRY J. SALAS (Advisor on Water Pollution Control CEPIS). Original Air Date: 1988 (Updated: September 1995). Lima Peru.

By: Ing. Freddy Guerra

www.elinsubca.com

Caracas, March, 4 of 2013

8 Responses to Outfall – Optimal in Wastewater Treatment.

Estanislao Aliaga Flores 7 July, 2013
Agradeceré tener acceso al diseño de esta metodología de disposición final de aguas residuales, dado que estudios preliminares pretenden descargas de este tipo en el algo Titicaca. (Peru Bolivia)
Dan Tobar Burgos 19 July, 2013
Bajo la normativa actual del Ecuador quien tiene la competencia para autorizar la colocación de un emisario submarino? requisitos… gracias
info@elinsubca.com 19 July, 2013
Estimado Sr. Estanislao Aliaga Flores, hemos recibido su comentario y le estaremos contactando a través de su correo electrónico para enviarle la información requerida y conocer más sobre su proyecto.
info@elinsubca.com 19 July, 2013
Estimado Sr. Dan Tobar Burgos, es el Ministerio del Ambiente de Ecuador la institución encargada de aprobar un proyecto de construcción de emisario submarino. Revise la NORMA DE CALIDAD AMBIENTAL Y DE DESCARGAS DE EFLUENTES: RECURSO AGUA. Le estaremos contactando a su correo personal para ampliar nuestra respuesta y conocer más sobre su proyecto.
Carlos De Freitas 8 October, 2013
Excelente Información, pero tengo las siguientes interrogantes. Que precauciones se deben tomar para evitar la obstrucción del difusor? y que mantenimiento debe aplicarse para la conservación del emisario?.
- info@elinsubca.com 9 October, 2013
  Hola Carlos, gracias por tu opinión. Sobre el difusor, éste debe ser diseñado de tal manera que en el caso poco probable de presentar una obstrucción (ya que debería removerse los sólidos en un tratamiento preliminar) se pueda limpiar a través de una tapa de servicio ubicado al final del mismo. En cuanto al mantenimiento del emisario, te indico que un emisario en HDPE diseñado e instalado adecuadamente podría considerarse prácticamente libre de mantenimiento, incluso por encima de los 60 años.
  
  Si lo crees conveniente podemos atender alguna necesidad específica de algún proyecto asesorándote vía skype en una primera reunión sin costo alguno.
Jorge G. Merizalde Dobles 23 April, 2015
¿Cuántos emisarios submarinos existen actualmente en operación en el Ecuador? Hay proyectos de implementación de nuevos emisarios submarinos?
- info@elinsubca.com 23 April, 2015
  Muchas gracias Sr. Jorge por su pregunta, le informamos que en la actualidad Ecuador no cuenta con Emisario Submarino alguno, por cuanto su legislación ambiental no contempla, al menos hasta ahora, el uso de Emisarios Submarinos como sistema de tratamiento de aguas residuales. Sabemos que existe un proyecto de reformas de ley desde el año 2014, por lo que creemos que en el futuro esta solución pueda beneficiar ampliamente a la población de Ecuador (así como a otros países latinoamericanos) en materia de saneamiento costero, lo cual abrirá grandes posibilidades de desarrollo a la industria del turismo.