Piedras Negras, Coahuila, Mexico
Piedras Negras, Coahuila, MexicoWastewater System Rehabilitation Project in Piedras Negras, Coahuila
Project Status: Completed

General Information
Sector
Wastewater
Sponsor
SISTEMA MUNICIPAL DE AGUAS Y SANEAMIENTO DE PIEDRAS NEGRAS COAHUILA
Benefited population
65,000
Certification date
May 8,2014
Financing
Project cost
US 0.14M
NADBank Funds
US 0.25M - NADBank Grant: CAP
Related documents
Background
In 2013, water service and wastewater collection coverage was estimated at 99.4% and 97.8%, respectively. All collected wastewater is conveyed to the city’s wastewater treatment plant, which is operated by the company AREMA under a 20-year concession agreement. The treatment plant has an installed capacity of 520 liters per second (lps) or 11.9 million gallons a day (mgd).
In June 2013, Piedras Negras experienced uncharacteristically heavy rains that caused flooding throughout the city and significantly damaged the existing wastewater collection infrastructure. Two sections of the Rio Bravo Collector collapsed, interrupting wastewater conveyance to the treatment plant and causing approximately 2.3 mgd of raw sewage to be
discharged into the Rio Grande. Manhole frames and covers located throughout the city also suffered substantial damage due to the floods, which has resulted in additional deterioration of the wastewater collection system.
Description
The project to repair the wastewater system includes the following
components:
- Replacement of two sections of the Rio Bravo Collector: the
Campo Venados and Escalante. - Replacement of the gravity main sewer collector at Arroyo El
Soldado to repair the connection at the Santa Maria subdivision. - Repairs in Lift Station No. 4, including desilting of the wet well,
the replacement of the perimeter fence and rehabilitation of the
access road to the lift station. - Repairs to 154 manhole frames and covers located throughout the
city.
Benefits
The project will ensure the proper operation of the wastewater collection infrastructure in Piedras Negras and will reduce environmental and health hazards associated with untreated wastewater discharges, thus providing a cleaner healthier environment for local residents, as well as for communities downstream. Specifically, the project will prevent up to 2.3 mgd of untreated wastewater discharges.