Wastewater Reuse in MexicoValley: Atotonilco WWTP

Jorge J. MalfeitoR&D Director (Acciona Agua)

©2015 Acciona Agua S.A.U. Todos los derechos reservados.

© 2015 Acciona Agua S.A.U. All rights reserved.

Presentation Outline

Introduction.

Drivers.

Primary objectives.

Mexico City drainage system.

Mezquital  (Tula) Valley.

Atotonilco plant key players.

Atotonilco WWTP key figures.

Design Flows.

Process Diagram.

Sludge production.

Conclusions.

Introduction: Water Balance in Mexico City

(B. Jiménez‐Cisneros, 2012)

Introduction: Atotonilco WWTPAtotonilco Waste Water Treatment Plant (WWTP) is thelargest wastewater treatment plant built in a singlephase.

It will be the largestsanitation project inMexico with significantsocial, environment andsustainable benefits.It will benefit 700,000people of the MezquitalValle.60% of the waste waterfrom the Valley of Mexicowill be treated.

DriversThe Valley of Mexico Basin has one of the country’slowest waste water treatment indices (6%),whichproduces pollution and a serious water imbalancein the basin.

BenefitsTo treat more than 60% of the waste waterproduced in the Valley of Mexico.To irrigate with treated waste water more than80 thousand hectares in the Tula Valley, thusenhancing the region’s agricultural potential.To restore the good condition sof the surfacewater bodies and streams that receive wastewater.To improve the sanitation conditions of over300.000 people who live inirrigation zones.

Primary objectives Protect the health of farm workers and their families.Prevent the spread of pollution in the region.Restore the Endhó dam and organically rid it of anycontaminants, facilitating advances in irrigationtechnology.

Mexico City drainage system

Mezquital Valley

Mezquital Valley (also call TulaValley) is located at 60 km northeastfrom the Metropolitan Zone of theMexico City in the Hidalgo State.

The wastewaters are used, withoutany treatment in a massive way, forforage crop irrigation.

Mexico City and the surroundingurban area are supplied with 85.7m3/s, and generate a wastewateraverage caudal of 60 m3/s.

Are irrigated more than 85.000 has.

Atotonilco plant key players

Total investment estimated (at 2014 prices) 710 millions USD.The construction of the wastewater treatment plant isperformed under the DBOT scheme (design, build, operateand transfer) with a concession for operation.Contract signed: January 7, 2010.

Winning consortium (ATVM):

• Promotora del Desarrollo de América Latina S.A. deC.V.• Controladora de Operaciones de Infraestructura,S.A de C.V.• Atlatec, S.A. de C.V.• Acciona Agua S.A.U.• Desarrollo y Construcciones Urbanas, S.A. de C.V.• Green Gas Pioneer Crossing, L.L.C.

ACCIONA Agua, Key Figures 2014 

© 2015 Acciona Agua S.A.U. All rights reserved.

Total population served (construction,O&M and services): 50 million.Worldwide leader in Reverse Osmosis(RO) desalination. More than 75desalination plants (2,5 million m3/dayof installed capacity).Wastewater, treatment and Reuse(more than 400 plants built).More than 100 conventional plantsoperating and 40 supply services.

Permanent offices

Atotonilco WWTP key figures

The average design flow is 35 m3/s with a maximum of42m3/s in the rainy season.However the maximum flow is up to 50m3/s.

The generated biogas willbe used in the plant forthermal and electricalenergy.The estimated generationof electricity is 200GWh/year.

Design Flows

DRY SEASON RAINING SEASONTREATMENT LINE AVERAGE MAXIMUN AVERAGE MAXIMUM

Convencional Treat. 23.0 30.0 27.6 33.0

Chemical Treat. 12.0 12.0 14.4 17.0

TOTAL 35.0 42.0 42.0 50.0

TOTAL TREATMENT CAPACITY : 1.041 hm3/Year

Process Diagram

SecundarySettling

Sludge production

The sludge comming from the pretreatmet is estimated in100.178 Tn/year.It will be use for sanitary filling.The biosolids production from the sludge treatment line (at28%) will be around 837.408 Tn/year (2.294 Tn/day).

The quality of the sluge is type C,in agreement with the standardNOM‐004‐SEMARNAT‐2002(SEMARNAT, 2002).It could be use in agricultural andfor soils recovery.

ConclusionsProvided the finished plantmeets each of its objectives,the Valley of Mexicopopulation will be granted afar better standard of living,with its agricultural sectorhaving a far better chance ofgrowth.

By improving upon the region’soverall service, coverage, andinefficiencies, Mexico can begin tomove away from its long history ofwater‐related hindrances.

© 2015 Acciona Agua S.A.U. All rights reserved.