Aguas Sanitarias y Santurce

Decidi escribir este post por una discusion relacionada al manejo de aguas sanitarias en sistemas que ya pasaron su vida util.  Este es otro monstruo completamente distinto al del pasado articulo, una planta de tratamiento funcional que necesita cambios.  Antigonum me menciono en particular los salideros sanitarios del Ca/no Martin Pe/na y de la Laguna del Condado.  Esos tienen el agravante de ocurrir de las tuberias sanitarias de las zonas historicas del Viejo San Juan.  Pero me anticipo.  Un poco de transfondo historico:

http://yosemite.epa.gov/opa/admpress.nsf/b853d6fe004acebf852572a000656840/cb6eed07941bf7768525716a004b895e!OpenDocument
(01060) San Juan, Puerto Rico – Sewage pump station failures still result in thousands of gallons of raw sewage spewing into streets and waterways across the Island. The U.S. Department of Justice (DOJ), acting on behalf of the U.S. Environmental Protection Agency (EPA), today filed a lawsuit in federal court charging the Puerto Rico Aqueduct and Sewer Authority (PRASA) and Compañia de Aguas, a PRASA contractor that has day-to-day control over the operations of the sewage treatment system, with numerous violations of the federal Clean Water Act. In its complaint, the federal government demands that PRASA and Compañia de Aguas assess each pump station in Puerto Rico to identify deficiencies and develop a comprehensive operation and maintenance plan to address the deficiencies and to bring each of PRASA’s pump station facilities into immediate compliance with the Clean Water Act.
"Raw sewage is a public health threat and the periodic pump station break downs are not acceptable," said William M. Muszynski, Acting EPA Regional Administrator. "EPA wants PRASA and Compañia de Aguas to implement an island-wide operation and maintenance assessment program so future raw sewage discharges are avoided."
According to a lawsuit filed today in federal Court in San Juan, PRASA and Compañia de Aguas have failed to properly maintain and operate many of its pump stations across the Island. PRASA and Compañia de Aguas operate approximately 520 pump stations throughout Puerto Rico. The complaint specifically alleges violations in at least 30 pump stations, which have discharged raw sewage into creeks, rivers, and the oceans of Puerto Rico. The chronic and systemic lack of proper operation and maintenance of the pump stations across the island have resulted in operational failures, constituting violations of the permits issued to PRASA for its wastewater treatment plants and of the Clean Water Act, which prohibits the discharge of pollutants into waterways of the U.S. without a permit. The federal government is specifically citing PRASA and Compañia de Aguas for violations at:
Colinas de Monte Carlo Pump Station in Rio Piedras
Colinas de Cupey Pump Station in Rio Peidras
El Conquistador II Punp Station in Trujillo Alto
Los Laureles Pneumatic Ejector Station in Rio Piedras
Lourdes Pneumatic Ejector Station in Rio Piedras
Villa Andalucia Pump Station in Rio Piedras
El Conquistador II Punp Station in Trujillo Alto
Puerto Nuevo Pneumatic Ejector Station in Hato Rey
Tropical Comerio Pump Station in Comerio
Cayey Main Pump Station in Cayey
Fomento Pump Station in Cayey
San Cristobal Pump Station in Cayey
Green Hills Pump Station in Guayama
El Terminal Publica Pump Station in Juncos
Cruz Rosario Pump Station in Morovis
Montellanos Pump Station in Morovis
Palmas del Sur Pump Station in Morovis
Vista Pump Station in Morovis
Cerromonte Pump Station in Corozal
Caliche Pump Station in Ciales
Las Guabas Pump Station in Ciales
Barrio Piñas Pump Station in Toa Alta
Villa Matilde Pump Station in Toa Alta
Cabo Rojo Main Pump Station in Cabo Rojo
Puerto Real Pump Station in Cabo Rojo
El Poly Pump Station in San German
Reparto Universidad Pump Station in San German
Santa Marta Pump Station in San German
El Submarino Pump Station in Lajas
The federal government is demanding full compliance with the Clean Water Act at these and all pump stations, the development of an island-wide operations and maintenance plan for all of PRASA’s pump stations, and civil penalties of up to $27,500 per day for each violation. EPA has met with PRASA and Compañia de Aguas repeatedly to discuss this matter. PRASA and Compañia de Aguas have 20 days to respond to the lawsuit.

Y esto fue en el 2001.  La orden sigue corriendo a esta fecha y se ha modificado.  Al presente hay un Mega Consent Decree entre EPA, el Departamento de Justicia Federal y Acueductos para resolver esta situacion de salideros sanitarios.  En el caso particular de San Juan y Rio Piedras, que descargan a la Planta Regional de Puerto Nuevo se requirio entre otras cosas hacer un estudio de infiltracion e influjo a la red de alcantarillado sanitario para determinar en que segmentos particulares ocurre exfiltracion (salideros sanitarios) y donde la tuberia esta lo suficientemente deteriorada para infiltrar grandes cantidades de aguas subterraneas y escorrentia pluvial (lluvia).

En el caso particular de Puerto Nuevo, el consorcio que cubria los proyectos de infraestructura de AAA en la region norte le otorgo el contrato a ENTECH (http://www.entecheng.com/services/civil-environmental-resources/wastewater-engineering.htm) con representacion local.  Los resultados particulares del estudio los desconozco pues el proyecto ha estado corriendo desde hace ya varios a/nos pero entre las cosas se tuvieron que levantar mapas de la red de alcantarillado, poner estaciones de medicion de flujo en varios puntos de la red sanitaria, y entrevistar personas que conocieran el area, incluyendo operaciones de alcantarillado para determinar puntos sujetos a salideros y con mucha infiltracion.

Conozco a uno de los subcontratistas que hicieron las mediciones de flujo y me comento de las dificultades particulares del segmento de la avenida Ponce de Leon, por el puente y la estacion Sagrado Corazon.  De otro conocido en EPA se de un gran salidero por el area del peque/no establo con caballos que colinda con el parque lineal Marti Coll.  Hay muchos mas, pero resumamos las que quedan cerca de las areas de Santurce.
Entre mas nos acercamos al casco de San Juan comenzamos a tropezar con tuberias de mas de 50 a/nos de construccion.  Rehabilitar estas tuberias, en un terreno con un nivel freatico (water table) tan alto no es facil.  Ademas tenemos issues de trafico en estas vias principales.  Asi que la politica publica siempre ha sido ignorar la reparacion hasta que no haya mas remedio.

Similarmente si entramos al Viejo San Juan, la cosa empeora.  La infraestructura, ademas de vieja, implica remover adoquines y hacer excavaciones con cuidado al ser una zona historica.

En cuanto a los estudios como tal, te incluyo un  ejemplo de lo que pide EPA (el caso es de Massachussets pero te da una idea http://www.mass.gov/dep/water/laws/iiguidln.pdf).  Otras jurisdicciones (y paises) reconocen la seriedad de esta situacion (de British Columbia:)

http://www.crd.bc.ca/wastewater/ii/index.htm

Reasons to Reduce Inflow & Infiltration

I&I Consumes Valuable Sewer Capacity

I&I consumes sewer capacity needed for future growth in the region.  It is very expensive to add capacity to existing sewers.

Damage to the Environment

Sewer overflows are damaging to the environment and sensitive ecosystems.

I&I is a Potential Health Hazard

Sewer overflows, whether into private residences and buildings, into parks and streets or into waterways, are potential health hazards.

Regulatory Requirements

British Columbia’s Municipal Sewage Regulation requires that no person allow a sanitary sewer overflow to occur during storm events with less than a 5-year return period (i.e., on average, there shall be no more than one overflow every five years) .

Inflow & Infiltration Detection

How Sources of I&I are Detected

Flow Monitoring – sewage flow rates are monitored at various locations within the municipal sewage collection system. The flow data is analyzed, along with rainfall data, to determine if there is excessive I&I within the study area.
Smoke Testing – a non-toxic, stainless, odourless, vegetable-based “smoke” is injected, under pressure, into a sanitary sewer manhole. If smoke escapes from a source not connected to the sanitary sewer system, this would indicate a sewer I&I cross-connection.
Dye Testing – non-toxic dye is added to an upstream freshwater source believed to be contributing to I&I. The downstream sanitary sewer is then monitored for traces of the dye to confirm the existence of a sewer cross-connection.
Closed Circuit Television Inspections – a video camera is sent through a sewer line to record the condition of the sewer. The video footage is analyzed for cracks, intrusions and leaks.
Inspections – building inspectors and trained maintenance personnel visually inspect and assess the condition of the sewer system.

Oye mira, alguien trabaja una tesis sobre el tema.  Un borrador aqui:
http://www.wpi.edu/Pubs/E-project/Available/E-project-051105-015848/unrestricted/Santurce_IQP_Final_Report.pdf

Y aqui algo del Programa del Estuario:
http://www.estuario.org/downloads/plan_de_manejo/APPENDIX.pdf
Sewage Treatment Collection System Overflows
Overflows from sewage pumping stations are a point source of pollution affecting the SJBE.
Several sewage pumping stations have discharged their waters into storm drains or the estuary’s
tributaries due to mechanical failures associated with over-capacity operations (EQB, 1992). Over
the past several years, improvements to the sewage collection system in the SJBE area have reduced
the number and frequency of pumping station overflows; however, these overflows do still occur. In
1999, citizens from the Vistamar Marina residential area, adjacent to the La Torrecilla Lagoon, formed
a group known as Ciudadanos del Mangle, to seek solutions to the overflows from the Vistamar
sewage collection system as well as other environmental problems affecting their community. This
group engaged a private laboratory to sample and analyze the quality of the receiving waters affected
by the discharges. The analysis revealed fecal coliform concentrations in the Guadalquivir and
Managua lakes, two man-made embayments in La Torrecilla Lagoon, as high as 62,500 colonies/
100mL and 1,400 colonies/100mL, respectively (High Technology Laboratory, 1999). These values
are in violation of the WQS for fecal coliforms applied to La Torrecilla Lagoon (400 colonies/100mL).
(See Table 1.) USEPA recently conducted inspections to identify existing problems in the operation
of sewage pumping stations in the SJBE (Eng. Pedro Modesto, USEPA, personal communication, 1999).
Bypasses from many pumping stations were confirmed. The implementation of a regular maintenance
and upgrading program is recommended in this Management Plan to address this problem.

Combined Sewer Overflows
Combined sewer overflows (CSOs) are another point source that contribute nutrients and
pathogens to the estuary. Combined sewers are pipes that carry both wastewater and stormwater.
During heavy rainfalls, combined wastewater and stormwater flows can exceed the capacity of the
sewer pipeline and/or the capacity of the receiving sewage treatment plant. Excess flows are then
diverted, discharging untreated sewage and contaminated stormwater directly into receiving
waterbodies. These excess flows are called combined sewer overflows. Combined sewers can
also overflow during dry weather due to structural problems in the drainage system, physical blockages
of the flow regulators, and ground water infiltration into the system (Horsley & Witten, Inc., 1995).
Although combined sewers are no longer constructed, they are still in operation in many older urban
areas such as the San Juan Islet, Miramar, and Santurce. Eliminating CSOs, through the construction
of a sewer system that would independently collect storm waters and sewage for their appropriate
disposal, is the most effective alternative for addressing this source of pollution. However, new
construction is very expensive and time consuming. As an alternative, a maintenance program to
repair collapsed and clogged pipelines could be initiated to stop the discharges that occur during dry
weather periods. This solution should also include sanitary sewers, since some of these could be
obstructed or collapsed, discharging their contents through manholes and reaching storm sewers
that eventually end up in the estuary (EQB, 1996; Junta de Calidad Ambiental, 1994, 1996). This
Management Plan recommends the control of CSO sewage discharges reaching storm water collection
systems such as the Baldorioty De Castro and Stop 18 storm water pumping stations. In the meantime,
opportunities to replace existing combined sewers should be identified when infrastructure
improvements are being planned or developed.

La mejor parte son los anejos...como puedes ver, no creo que sean muy populares con los desarrolladores o los habitantes de Cantera.  Solo para que tengas una idea de lo que implica un estudio, este es el mapa de una red simple, la de la planta de aguas usadas de Isabela:

Es un hecho, hay que resolver el problema de los salideros.  EPA realmente le ha dado duro :
http://cfpub.epa.gov/npdes/cso/cpolicy.cfm
http://cfpub.epa.gov/npdes/home.cfm?program_id=5
http://cfpub.epa.gov/npdes/cso/ninecontrols.cfm?program_id=5

Estableciendo un programa de nueve puntos minimos:

Combined Sewer Overflows
Nine Minimum Controls

1. Proper operation and regular maintenance programs for the sewer system and the CSOs
2. Maximum use of the collection system for storage
3. Review and modification of pretreatment requirements to assure CSO impacts are minimized
4. Maximization of flow to the publicly owned treatment works for treatment
5. Prohibition of CSOs during dry weather
6. Control of solid and floatable materials in CSOs
7. Pollution prevention
8. Public notification to ensure that the public receives adequate notification of CSO occurrences and CSO impacts
9. Monitoring to effectively characterize CSO impacts and the efficacy of CSO controls

No hay que tener dos dedos de frente para saber como esta Puerto Rico y sobre todo la AAA respecto a este programa.  Estamos en el 2010 y ni siquiera tenemos unos buenos mapas de las redes de distribucion sanitarias y de agua potable.  Y eso es clave.  Si conoces tu red, la puedes monitorizar.  Ejemplos de otras jurisdicciones (una busqueda rapida en google me da estos ejemplos):
http://www.mwrd.org/irj/portal/anonymous/overview
http://www.adsenv.com/default.aspx?id=155
http://www.flowworks.com/features/wastewater

Articulo sobre rehabilitacion de sistemas antiguos:
http://www.adsenv.com/default.aspx?id=233

Lo cierro aqui.  Me despegue demasiado.  Me fui muy tecnico.  Pero creo que expuse aqui que para resolver el problema de salideros hay que meter chavos y establecer la politica publica para detectar el problema.  Sin embargo aqui todavia seguimos en politiqueria barata y en darle contratos a los favorecidos del gobierno de turno.