I. Introduction

Water, a vital resource essential for life, has also become a pressing national security matter¹ requiring international cooperation. The international community has confronted the problem of water quality and availability by gradually adopting principles for the integrated management of water resources. This has led many countries to adopt policies, strategies, domestic laws, and information systems, as well as coordination, financing, and enforcement mechanisms² aimed at regulating the water management cycle from freshwater extraction, distribution and use, to reclamation, treatment, reuse and ultimate return to the environment.³

Despite these efforts, once water has been used and becomes wastewater,⁴ its subsequent fate is often ignored. Wastewater is one of the principal causes of water and coastal ecosystem pollution, and poses a threat to food security, drinking water access, public health, and ecosystem survival. Nevertheless, wastewater management is one of the most overlooked factors in Mexican environmental policy. This neglect has not only led to increased poverty but has also become an impediment to economic development.⁵ A desirable paradigm change would include wastewater as a reliable alternative source of water. This would require a change in how wastewater is managed, “shifting the paradigm from ‘treatment and disposal’ to ‘reuse, recycle and recover’”.⁶ This paradigm shift could transform wastewater from an environmental problem into a solution to one of the most significant challenges facing humanity.

The prevalence of wastewater-related issues and problems tends to vary in direct proportion to a country’s income level. On average, high-income countries treat about 70% of the wastewater they generate, whereas this percentage drops to 38% for medium-income countries, 28% for lower-income countries, and 8% for the lowest-income countries.⁷ The absence of adequate wastewater treatment systems exacerbates poverty and increases health problems by directly exposing the population to polluted wastewater.

In Mexico, wastewater is reused in large quantities. Despite the fact that 94% of the water supply destined for individual use has been disinfected, only 58.3% of the wastewater collected through sewer systems is treated to improve its quality before being reused or returned to a body of water.⁸ As a result, water for human use, whether taken from surface or groundwater sources, is often contaminated by pathogenic microorganisms, particularly fecal coliforms.⁹ Recognizing the gravity of this problem, Mexico has adopted the Agenda 2030 and its sustainable development goal (SDG) regarding water resources, both of which address issues beyond water supply and treatment. In particular, the SDG Target 6.3 provides that signatory countries commit, “by 2030, [to] improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally”.¹⁰

Achieving these goals will require a paradigm change that envisions wastewater as a solution to the problem of inadequate water supply and treatment. Such a change, however, depends on the existence of a comprehensive and effective legal framework concerning wastewater which ensures compliance by both individuals and organizations in order to promote the collective interest.¹¹ Thus, public policies and wastewater management goals need to be implemented in the form of specific laws and regulations which clearly define the responsibilities assigned to the various involved parties. The effectiveness of such laws largely depends on how these responsibilities are defined and implemented at the federal, state, and municipal levels.¹²

The problems associated with wastewater management in Mexico begin with the country’s regulatory framework, which is characterized by overlapping federal, state, and municipal regulatory layers which inhibit compliance. Specific case studies examining these issues in the national context are needed to help communities understand and anticipate what constraints or problems they may face when attempting to better manage their water resources. This paper provides a comprehensive overview of the existing legal framework regarding wastewater resources and discharges, and a systematic assessment of its efficacy, at all three levels of government.

The state of Baja California Sur (BCS) was selected for examination because it is representative of regions that are highly vulnerable to water scarcity. In that state, the principal source of water is aquifer extraction which highlights the importance of the link between water quality and availability given the fact that overexploitation has given rise to saline water intrusion. Wastewater could become an additional source of water for the state, but the current legal framework complicates and impedes its efficient use and management. A comprehensive, systematic analysis of wastewater regulations is urgently needed to assist in the formulation of new public policies which encourage wastewater treatment and reuse in order to confront the problems of water quantity and quality in BCS.

In order to perform a systematic analysis of the existing wastewater legislation at the federal, state, and municipal levels, a comprehensive survey of documents on environmental law and the related legal framework regarding wastewater resources was conducted using the methodology developed by Dr. María del Carmen Carmona.¹³ Her approach provides a new perspective as well as a legal basis for analyzing the effectiveness of legal frameworks so that legislative reforms can be envisioned and proposed which both encourage compliance and facilitate enforcement.¹⁴

Carmona’s methodological framework is comprised of the following steps: a constitutional analysis; a hierarchization of the sources of law; an analysis of the spheres of validity (spatial, temporal, material, and personal); and, a dynamic analysis. We will begin with a constitutional analysis, identifying the specific constitutional provisions that provide the foundation for the legal framework regarding wastewater. Once this has been completed, a deeper analysis of the specific wastewater-related provisions may be performed. This method is predicated on a formal analysis, that is, a systematic analysis of the sources of law and their hierarchical structure, as well as an explication of the particular type of legal system in which they are embedded.¹⁵

II. Legal Background Regarding Wastewater in Mexico

The Mexican regulatory framework regarding wastewater has two sources, one stemming from water-related legislation, the other from environmental law. Water law in general predates environmental law as such. In this way, the first relevant statute to be enacted was the Mexican Transportation Act of 1888 (Ley General de Vías Generales de Comunicación). This was followed by the Use of Federal Waters Act of 1910 (Ley sobre Aprovechamiento de Aguas de Jurisdicción Federal), the Irrigation with Federal Waters Act of 1926 (Ley sobre Irrigación con Aguas Federales), the Nationally Owned Waters Act of 1934 (Ley de Aguas de Propiedad Nacional), and finally, the Federal Waters Act of 1972 (Ley Federal de Aguas). Subsequent amendments and additions to the Federal Waters Act resulted in the current National Waters Act of 1992,¹⁶ which was last amended in 2020.

The first environmental regulations developed out of a need to protect human health from various sources of pollution. The first such law to be enacted was the Federal Environmental Pollution Prevention and Control Act of 1971 (Ley Federal para Prevenir y Controlar la Contaminación Ambiental).¹⁷ It had three regulations:

After 1971, a number of constitutional and legal reforms were enacted with the objective of protecting the environment; however, these reforms continued to be primarily targeted to the protection of human health. In terms of institutional changes, in 1972, the post of Environmental Improvement Undersecretary (Subsecretaría de Mejoramiento al Ambiente) was created within the Secretary of Health. However, the powers deriving from the Federal Environmental Pollution Prevention and Control Act were sector-specific, with each federal department being assigned distinct responsibilities. For example, the Secretary of Water Resources (Secretaría de Recursos Hidráulicos) had jurisdiction over the prevention and control of water pollution, the Secretary of Agriculture and Livestock (Secretaría de Agricultura y Ganadería) oversaw the prevention and control of soil contamination, and the Secretary of Industry and Commerce (Secretaría de Industria y Comercio) was responsible for the prevention of contamination resulting from industrial and commercial activity.²¹

It was not until 1982 that the first Federal Environmental Protection Act (Ley Federal de Protección al Ambiente) was enacted. Pursuant to this Act, various environmental responsibilities were consolidated and centralized which was a significant first step toward the effective protection of the environment and the nation’s natural resources. This Act was ultimately superseded by the current Mexican Environmental Protection Act of 1988 (Ley General del Equilibrio Ecológico y la Protección al Ambiente).²² LGEEPA has been subsequently amended several times, most significantly in 1996. LGEEPA’s Title Four, “Environmental Protection”, Chapter III, “Prevention and Control of Pollution of Water and Aquatic Ecosystems”, contains the wastewater-related provisions.²³

The Mexican Constitution (Constitución Política de los Estados Unidos Mexicanos)²⁴ has also undergone several revisions and amendments, most significantly to Article 4, in 1999 and 2012, which introduced the following rights fundamental to wastewater regulation:

All persons have the right to a healthy environment for their development and well-being. The State shall guarantee the effectiveness of this right. Anyone who causes environmental damage or degradation incurs the corresponding liability, as prescribed by law.²⁵

Everyone has the right of access to, disposal of, and treatment of sufficient quantities of clean water for personal and domestic consumption, in an acceptable form and at an affordable cost. The State shall guarantee this right and the law shall establish the bases, assistance, and modalities for equitable and sustainable access to, and use of, water resources, establishing the participation of the Federation, the federative entities [states], and the municipalities, as well as the participation of the citizens, in the achievement of these ends.²⁶

Another federal law related to wastewater regulation is the Federal Duties Act (Ley Federal de Derechos). The 1982 version of this Act included fees for the use and appropriation of national surface water and groundwater, and the 1991 version was amended to include the assessment of fees for contaminated wastewater discharges.

The Water Pollution Prevention and Control Regulation of 1973 was abolished by the Regulations of the National Waters Act.²⁷ Due to the superseding authority of the National Waters Act over LGEEPA, this new regulation became the effective regulatory law governing the prevention and control of water pollution.²⁸ This legislative history reveals an abundant but fragmented legal framework regarding wastewater regulation. Due to the different levels of jurisdiction, spheres of application, and hierarchies, the resulting operational framework is complex and can be difficult to navigate.

III. Theoretical Framework

Since the literature on wastewater legislation is limited, we opted to make use of an indirect bibliography in order to examine current wastewater regulation. Agenda 21, a non-binding action plan developed during the Earth Summit of the United Nations Conference on Environment and Development held in Rio de Janeiro, Brazil, in 1992, establishes that all member states, according to their capacity and available resources, should implement effective programs to prevent and control water pollution. Such programs are to be based on a combination of strategies designed to reduce pollution, assess environmental impacts, and uphold mandatory standards applicable to wastewater discharges.²⁹

Agenda 21 sets forth the following objectives related to the prevention and control of water pollution:³⁰

Achieving these objectives depends on the existence of both effective institutions and a corresponding, complementary legal framework at the national level. In Mexico, the principles underlying these objectives do, in fact, appear in the regulatory framework. However, the persistence of wastewater-related problems leads to the conclusion that either the current laws are inadequate, or they are not being effectively applied or enforced.

According to Anthony Heyes, given both the increasing number and increasingly coercive nature of environmental laws, one might assume that levels of compliance have improved. However, compliance depends on stable and predictable enforcement. To this end, governmental authorities must implement an effective compliance program.³¹ At the outset, any compliance regime requires the dissemination of clear, accurate information that is easily accessed, interpreted and understood.³² In the area of wastewater regulation, this first step involves compiling and consolidating all applicable laws and regulations. Once this has been done, the effectiveness of the entire regulatory apparatus in promoting the sustainable management of water resources can be assessed, and the need for further amendments or reforms can be more easily identified. As Ortiz Rendón has observed, “Without accurate knowledge of the problem, it is impossible to implement sustainable policies to address them”.³³

Along these same lines, Carmona points out that the OECD already has identified one particular challenge facing Mexico that pertains to water management in Mexico: the need for implementing legislation targeted to the reduction of pollution and the protection of nature, including increasing the number of inspections and the level of regulatory compliance.³⁴ In that regard, as González states, “Good water governance calls for the use of mechanisms such as laws and regulations, effective policy, adequate governmental organization, requisite infrastructure, and a culture of efficient use and preservation of water resources”.³⁵ González maintains that sustainable development also requires an explicit system of incentives to encourage the efficient and responsible use of water, and to help preserve water quality. Such a system can only be achieved with a corresponding legal framework that specifically articulates the nation’s current needs. He emphasizes that the law should be simple, clear, easy to understand, straightforwardly applicable, and include regulations that define and explain all relevant procedures.³⁶

With the foregoing in mind, our analysis will focus on the Mexican legal framework and international guidelines pertaining to wastewater, since they are the platform for the effectiveness of water management policies and enforcement mechanisms, that, as Gilabert-Alarcón states, change with each new presidential administration, resulting in the deterioration in both water and sanitation services.³⁷

IV. Study Area: Baja California Sur

BCS is a semi-desert state in northwestern Mexico occupying the southern half of the Baja California peninsula. It is bounded on the north by the state of Baja California, which lies above the 28th parallel, on the east by the Gulf of California, and on the south and west by the Pacific Ocean. It occupies 73,475 km², or 3.8% of Mexico’s territory,³⁸ and is divided into five municipalities, from north to south: Mulegé, Loreto, Comondú, La Paz, and Los Cabos.

Map of Baja California Sur³⁹  

The Baja California peninsula is located in one of the most arid regions of the country with a mean annual precipitation 77% lower than the national average, which limits its prospects for social, economic, and environmental development.⁴⁰ BCS receives 0-400 mm of rainfall annually. At higher elevations, rainfall reaches an average of 700 mm, while the mean total annual precipitation in the state is less than 200 mm.⁴¹ The climate at lower elevations is dry desert; the temperature exceeds 40°C in the summer and falls below 0°C during the winter. Only the Los Cabos region has a sub-humid, temperate climate due to the influence of cyclones.⁴²

The state’s population is 712,029, which amounts to 0.6% of Mexico’s inhabitants.⁴³ The census currently underway is expected to increase that number to one million. The tourism boom in Los Cabos has been a strong driver of both immigration and water demand, increasing the pressure on the region’s water resources.⁴⁴ From 2000 to 2010, the population of BCS grew by 50%, resulting in a corresponding reduction in annual per capita water availability, which fell to 785 m³. This state is, therefore, classified as one experiencing water scarcity.⁴⁵

The BCS State Climate Action Plan acknowledges that the only reliable source of fresh water in the state is groundwater, which is recharged by flooding and runoff from intense rainfall. However, groundwater is being mined from all available aquifers at a higher rate than it can be recharged, resulting in seawater infiltration.⁴⁶ The main sources of water pollution in the state are untreated municipal, industrial, and agricultural discharges, the low efficiency of treatment plants, infiltration from septic systems, and inadequately sited or uncovered garbage dumps.⁴⁷

The Vision 2030 Regional Water Program recognizes that the water infrastructure in Baja California is insufficient and that wastewater treatment does not, in most cases, comply with the Official Mexican Standard of quality. It further states that there is widespread noncompliance with laws and regulations governing wastewater control, solid waste management, and waste disposal.⁴⁸

V. Systematic Analysis of the Legal Framework Regarding Wastewater

A systematic, step-by-step analysis of the legal framework concerning wastewater can assist interested parties in navigating the complex regulatory scheme and managing the information relevant to their roles. We present such an analysis in the following sections.

VI. Conclusions

This analysis and schematization of Mexico’s legal framework regarding wastewater can be used as a guide by legislators, public servants, academics, and members of the general public who wish to obtain a better understanding of how it operates. As previously stated, it is not sufficient to analyze the federal provisions alone. Due to the overlapping jurisdictions of the different levels of government on this subject, state and municipal provisions must also be included in any analysis. To achieve a level of wastewater management compatible with environmental sustainability and protect the nation’s water resources for current and future generations, the effectiveness of this legal framework must be maximized. This can only be accomplished after understanding how the entire integrated system of applicable laws and public policies functions, and then determining which laws need to be amended, and in what manner.

To help clarify the extensive and intricate legal framework involving wastewater in Mexico, and, in particular, to assess the compatibility of the various wastewater-related regulations existing at the federal, state, and municipal levels, we conducted a systematic analysis of this corpus. Further research can capitalize on this first step in order to evaluate the overall effectiveness of the current legal framework. Although much progress has been made in the implementation of laws and standards governing wastewater at the federal, state, and local levels, the critical water shortage in Mexico and in BCS -a waterstressed state anticipating a rapid increase in population and water demand- suggests a need for the development and implementation of new strategies for water conservation. At a minimum, such strategies should include vastly increasing the treatment and reuse of wastewater, and establishing strict water reclamation and recycling standards. These will only be achieved through the enactment of effective, targeted regulations and a strict enforcement regime.

The development of wastewater legislation is constantly evolving as specific problems become apparent. This development parallels a similar trend in environmental law in general. However, the aim of most current regulation is directed principally at the prevention of pollution. Under this approach, the generation, collection, treatment, reuse, and final disposal of wastewater are addressed by means of regulations dealing with discharge licenses and permits, various fees and duties, and the enforcement of official standards covering water quality. At the municipal level, the bylaws enacted typically limit their focus to the regulation of public services, such as water delivery and sanitation. Although the concept of wastewater reuse does appear in these regulations and has been incorporated into development and environmental plans and programs at various levels, it is not currently a legally enforceable obligation. A paradigm shift recognizing wastewater reuse as a possible solution to the issue of water scarcity will require amending federal, state, and municipal legislation, converting wastewater reuse into a legal obligation, and thereby placing it on an equal footing with wastewater treatment.

A new line of research is therefore needed on the effectiveness of the currently existing, incentives-based model encouraging wastewater reuse, and, on the benefits that a mandatory approach would require for it to be viable. In agricultural production, for example, wastewater is insufficiently regulated, and producers often find that absorbing fines is cheaper than treating wastewater. New legislative measures must eliminate these types of economic disincentives to conservation. In the short term, wastewater regulations should be amended to require the full treatment of wastewater so that it is brought up to a reusable standard. For this to occur, the law must cover the entire process, from generation to routing to treatment and reuse. However, given the fragmented legal framework currently in place in BCS, with each governmental authority being responsible for only a specific part of the wastewater process, any reuse regime would be rendered ineffective. This is a significant problem considering BCS is a region where, at present, only 58.3% of the wastewater collected through the state’s sewer systems is being treated before being reused or returned to a body of water.

The enforcement apparatus of the current legal framework related to wastewater is another factor that must be analyzed in order to ascertain its effectiveness. As stated above, the existence of overlapping responsibilities has complicated the issue of enforcement. Resolution of this problem will require encouraging coordination among authorities at the various levels, providing adequate institutional funding, and specifically defining the roles played by each governmental agency.

The most significant obstacle to the completion of this study was locating and compiling the relevant information and legislation due to the fact that there is no uniformity among the five municipalities of BCS, and not all regulations and bylaws are available online. Municipal bylaws are particularly elusive: some do not exist in any accessible form, others are outdated, and still others have not been renewed since 2018. None of these provisions are included at the website of the federal Congress, and municipal sites are frequently out of date or offline altogether. An important first step in facilitating research and investigation in this area would be the creation of a straightforward and up-to-date online compilation of all municipal laws, one that is both publicly accessible and easy to navigate.