Decentralised Public Utility for Drinking Water, Sewerage and Sanitation Services of Metepec
DRINKING WATER, SEWERAGE AND SANITATION
OF METEPEC
"SYSTEM FOR THE CONTROL, GRINDING,
SEPARATION OF SOLID WASTE OF LAS JARAS
CANAL, AND REGULATION AND INFILTRATION
WORKS FOR RAINWATER CONDUCTED
THROUGH THE WEST INTERCEPTOR OF
METEPEC, MEXICO"
LOCATION: METEPEC, MEXICO. Decentralised Public Utility for Drinking Water, Sewerage and
Sanitation Services of Metepec
"SYSTEM FOR THE CONTROL, GRINDING, SEPARATION OF SOLID WASTE OF LAS
JARAS CANAL, AND REGULATION AND INFILTRATION WORKS FOR RAINWATER
CONDUCTED THROUGH THE WEST INTERCEPTOR OF METEPEC, MEXICO"
The modifications to the environment in large urban centres and the lack of city planning
generate for the stormwater runoff draining channels to be modified as well, from its
runway rectification, its conversion to wastewater open channels, to the invasion of its
runway, obstruction of the hydraulic section, correction in thin sections, and in some
cases, their total elimination.
In the municipality of Metepec with the piping of the “El Arenal Jaras” stream has suffered
serious consequences of these modifications and lack of works planning due to the rapid
urban population growth, along its runway it receives sewerage discharge from towns
settled on its banks (Santiago Tlacotepec, Capultitlan, San Felipe Tlalmimilolpan, La
Cañada, Dos Rios, Los Alamos and La Curva), in the section entering the town of
Metepec, it goes from one open section to a 1.83 metres wide collector with a 1.07 metres
wide parallel collector to convey wastewater during the dry season.
In this last area rainfall has caused serious problems with the flow obstruction at the
entrance and the lack of conveying capacity (about 12 m3/sec arrive to the area),
overflowing and flooding a large section of two neighbourhoods with serious
consequences and economic losses to the inhabitants of this area of the municipality.
Decentralised Public Utility for Drinking Water, Sewerage and Sanitation Services of Metepec
This year CAEM completed the construction of the West Metepec interceptor, a facility of
1.52 cm wide Ø 4500 linear metres pipe, from the intersection of H. Enriquez Street and
the Jaras Canal to the mines area of San Miguel Totocuitlapilco.
This project was divided into three stages: the first with a diversion structure to divert storm
water into the interceptor, controlling waste and other solids from entering; the second with
the interceptor already in use; and thirdly, a buffer structure, a regulating reservoir and a
structure that allows for the maximum rainwater use.
For this purpose APAS developed the complementary projects:
"SYSTEM FOR THE CONTROL, GRINDING, SEPARATION OF SOLID WASTE OF LAS
JARAS CANAL, AND REGULATION AND INFILTRATION WORKS FOR RAINWATER
CONDUCTED THROUGH THE WEST INTERCEPTOR OF METEPEC, MEXICO"
These projects are considered innovative in the area as 5.0 m3/sec of storm water will be
diverted, which greatly affect urban and suburban municipality, significantly reducing flood
risks, and also once such waters are conducted, the buffer structure will be constructed in
the tunnels and 46 infiltration wells that will recharge the aquifer in the valley.
The structure of the "SYSTEM FOR THE CONTROL, GRINDING, SEPARATION OF
SOLID WASTE OF LAS JARAS CANAL, the storm interceptor tank project, which is really
a diversion structure with a geometry that will derive the maximum flow that the 1.52 m
rainfall interceptor takes, based on information obtained in the hydrological, geotechnical
and structural study, there are plans to carry out the following activities:
Decentralised Public Utility for Drinking Water, Sewerage and Sanitation Services of Metepec
A) stream channel rectification and lining of El Arenal for the return period of 20 years in a
280 metres length of hydraulic design for an expenditure of 12.68 m3/s
B) Supply and installation in this section of two grid separation stations for coarse solids
and the second of fine opening, automatic retention, control and removal of solid waste,
electromechanical and structural design.
C) Construction and equipment of control, operation and monitoring station with power
generation emergency plant with a level control warning system for timely prevention of
flooding connected to the civil protection system.
These actions will allow deriving about 5.0 m3/sec of stormwater; retaining solids and
preventing flooding problems in the urban area.
In reference to the “REGULATION AND INFILTRATION WORKS FOR RAINWATER
CONDUCTED THROUGH THE WEST INTERCEPTOR OF METEPEC, MEXICO”,
previous studies have been conducted for the stormwater runoff derivation through a relief
collector to the area of tunnels located south of the municipality on the border with the
Mexicaltzingo municipality including hydrological, geotechnical, permeability and structural
analysis.
This area of tunnels has been heavily impacted due to the extraction of stone materials,
mainly sand; its size is considerable, and today it is used only to receive gravel and other
materials, resulting in a polluted and deserted area with no type of restrictions.
Decentralised Public Utility for Drinking Water, Sewerage and Sanitation Services of Metepec
Therefore, this Utility seeks to provide a new sustainable use, as if groundwater recharge
projects are not structured and executed in this area with the characteristics for infiltration
according to the studies carried out, a golden opportunity will be lost since, on the one
hand, the municipality has just closed the tunnel receiving municipal waste, therefore it
would be likely to aim its use in this activity, or due to the high pressure in the housing
sector that envisions this zone as a large area of very short-term capital gains, given the
important roads been built recently in the Metepec municipality.
The project concepts to discharge into the regulatory reservoir and infiltration were
developed under the following considerations:
A reservoir is being designed in the selected site that meets the characteristics of a
regulating reservoir for storm water control, being defined the areas available for this
purpose; we have calculated the volumes and geometries that meet this objective and the
site in an area of 2.26 hectares.
The role of regulation is basic as it is conditioned on the ability of the soil to absorb water,
which is associated with the permeability of the site, for which soil mechanics and geohydrology (permeability analysis) studies were conducted.
Based on the studies, we have calculated the hydraulic balance of the reservoir for filling
and emptying speed that the soil will allow, as well as extra exceeding.
Based on the soil mechanics study and determining the absorption capacity, for which two
tests were conducted at 20.0 and 30.0 metres deep, the result was that the site where the
regulating and absorption tank will be built is located on strata of sandy loam of low
permeability, drills were made with a tri-cone drill bit of 4 "in diameter for the permeability
test.
The infiltration wells will be drilled to 30 metres average, with an inner diameter of 80 cm
and an exterior of 1.80 will have a ½ to ¾ inches gravel filter, geotextile fabric on the walls
and slotted casing pipe which allow water to be injected into the aquifer.
In short, this project is considered innovative as instead of seeking a fast and easy way out
to rainwater, this will be lead to an abandoned mining area, previously used as rubbish
dumps area, where a regulating reservoir will be constructed. Rainwater infiltration will be
achieved through special structures, thus flooding in the urban area will be prevented and
groundwater recharge in the valley of Toluca will be ensured, becoming a regional project
that will benefit the neighbouring municipalities.
In addition to the above, stored rainwater can be used in a myriad of activities such as
irrigation, car washing, shopping centres, etc.
This project can be extended to other municipalities in the Valley of Toluca, mainly Toluca
and Zinacantepec, where they also have this kind of abandoned mine structures in which
this concept could be replicated, and thus rescuing and using those areas for projects in
the long-term.
With the implementation of this action, it is intended to directly benefit a population of
50,000 inhabitants of the towns of Toluca, Metepec and especially San Mateo Atenco, as
water from this channel is poured into the Lerma River.
Decentralised Public Utility for Drinking Water, Sewerage and Sanitation Services of Metepec