Basic sanitation and proper disposal of wastewater are essential for the preservation of water resources and public health. In Brazil, Law No. 11,445/2007 (Legal Framework for Basic Sanitation), updated by Law No. 14,026/2020, defines sewage disposal as a public service. It also gives service providers and regulatory agencies the authority to establish the conditions for the use of sewer networks.

For companies, this responsibility is even greater. Depending on the production process, the effluents generated can have very different physical, chemical, and biological characteristics from those of domestic sewage: high organic load, oils and greases, heavy metals, solvents, pH outside the neutral range, high temperature, or toxic substances. These contaminants can cause corrosion, obstruction, and incrustation in pipes. They can also generate toxic or flammable gases and inhibit the biological processes of Wastewater Treatment Plants (WWTPs). There are also cases where they pass through treatment without removal and reach water bodies.

Therefore, it is the generator's responsibility to characterize their effluents before discharging them into the public system. It is necessary to verify if they meet the established standards and what control or pre-treatment measures are needed to ensure safe discharge.

It is in this context that PRECEND (Program for Receiving and Controlling Non-Domestic Effluents), created by COPASA (Sanitation Company of Minas Gerais), comes into play. The program regulates the receipt, in the public sewage system, of effluents generated by industrial, commercial, and service activities.

But how exactly does PRECEND work? Who needs to be part of it? How do you join the program? And what are the consequences for those who don't follow its rules?

In this article, we explain the main points of PRECEND and the importance of your company properly disposing of its effluents.

What is PRECEND?

PRECEND is COPASA's program focused on the control and reception of non-domestic wastewater (NDW) in the public sewage system. It began as a program to control industrial wastewater and was expanded to cover all non-domestic wastewater, at which point it adopted its current name. In 2021, it was reformulated and renamed "New PRECEND".

At the momentThe program is governed by COPASA Technical Standard T.187/6, approved by ARSAE-MG Resolution No. 117/2018. This standard establishes the discharge conditions and maximum limits for physicochemical parameters such as pH, temperature, settleable solids, oils and greases, COD/BOD, sulfides, sulfates, anionic surfactants, and metals. To be accepted into the sewer system and directed to COPASA treatment plants, non-domestic effluent must strictly meet these standards.

In this way, PRECEND contributes to protecting sewer networks and wastewater treatment plants, ensuring treatment efficiency, preventing environmental impacts, and preserving water resources.

Who Needs to Join PRECEND?

Wastewater generated in cities originates from both domestic and non-domestic sources. Non-domestic effluent is defined as "liquid waste resulting from the use of water for industrial, commercial, or service-providing purposes that acquires specific characteristics depending on the process employed." This means that the need for control is determined by the characteristics of the effluent, not just the size of the company. Therefore, every enterprise that generates non-domestic effluent must assess its characteristics before discharging it into the public sewer system.

Here are some examples, showing the typical contaminants for each activity:

• Industries: They vary depending on the process; they can include metals, solvents, dyes, high organic load, and extreme pH.
• Restaurants and industrial kitchens: Oils and greases of vegetable and animal origin, solids and high organic load.
• Hospitals and healthcare facilities: Chemical residues, pharmaceuticals, sanitizing agents, and microbiological load.
• Laboratories: chemical reagents, solvents and metals.
• Auto repair shops, car washes, bus companies, car dealerships, and gas stations: Mineral oils, fuels, BTEX, detergents, metals and solids.
• Among other venturessuch as laundromats, printing shops, pet shops, supermarkets, and meat processing plants.

Each activity requires its own diagnosis, with specific monitoring parameters and control measures.

It is worth noting that, in municipalities such as Belo Horizonte and Contagem, the licensing of non-residential developments involves the presentation of a report from COPASA (the water and sewage company). Therefore, registration with PRECEND (the regulatory agency) may also be required to obtain building permits.

What are the program's objectives?

According to COPASA, the objectives of PRECEND are:

1. Regularize the establishment with the environmental agency. with regard to liquid effluents.
2. Protect the drainage system It protects against corrosion, clogging, scaling, and toxic fumes caused by effluent, as well as preventing explosion and flammability risks.
3. Preventing the release of pollutants that pass through wastewater treatment plants without proper removal and can deteriorate waterways.
4. To prevent the release of effluents that could disrupt the treatment process., such as substances that inhibit the microbiological activity of biological processes.
5. To enable the reuse of final effluent from wastewater treatment plants. in the industry.
6. Reduce health risks for workers. who operate and maintain the public sewage system.

What does the legislation say about the discharge of effluents?

The discharge of non-domestic wastewater into the public sewer system follows a set of regulations that protect both the sewage system and the environment:

• CONAMA Resolution No. 430/2011: It establishes the conditions and standards for effluent discharge. For indirect discharge, carried out through the sewer system, it refers to the regulations of the environmental agency and the guidelines of the system operator.
• Joint Normative Resolution COPAM/CERH-MG No. 8/2022: In Minas Gerais, it defines the classification of water bodies and the standards for effluent discharge.
• ARSAE-MG Resolution No. 040/2013: It establishes the general conditions for the provision of water and sewage services by regulated providers.
• COPASA Technical Standard T.187/6: It details the specific limits and conditions for receiving non-domestic wastewater.

Resolution ARSAE No. 040/2013, cited by COPASA in its documentation, establishes that it is not permitted to discharge non-domestic effluents into the sewer system without prior treatment if they may damage or obstruct the system, interfere with the wastewater treatment process, or cause damage to the environment, public property, or third parties.

The same resolution also considers the discharge of non-domestic effluents that, due to their characteristics, require prior treatment to be irregular. In practice, when the effluent does not comply with the discharge limits, the company must adopt control measures at the source or install pre-treatment systems before discharge. Examples include grease traps, oil-water separators, equalization tanks, pH neutralization, or physicochemical processes.

Therefore, before discharging its effluents into the public sewer system, the company must characterize them through sampling and laboratory analysis, compare them to applicable limits and, when necessary, implement appropriate treatment. The collection and preservation of samples must follow recognized technical standards, such as ABNT NBR 9898 and... Standard Methods for the Examination of Water and Wastewater (SMEWW). Thus, the results are representative and accepted by the concessionaire.

How to join PRECEND?

1. Inspection request
The first step is to request an inspection of the building's sewage installations from COPASA. This request can be made by calling 115, in person at the local office, the nearest customer service agency, or through the online portal. The inspection can also be carried out when the building requests a sewage connection.

2. Technical visit by COPASA
After the request, a COPASA professional conducts a technical visit. During this visit, the sewage installations, the origin of the effluents generated, and the situation of the establishment are evaluated, and the necessary procedures for compliance are defined.

3. Completing the Application Form
During the visit, the entrepreneur receives the "Application for Entry into PRECEND" form. The document must be completed with information about the establishment (activity, processes, water consumption, and effluent generation points) and sent to COPASA.

4. Issuance of the Entry Certificate
With the documentation received, COPASA issues the Declaration of Entry into PRECEND. This document formalizes the company's entry into the program and sets the deadline for submitting the Technical Project.

The Declaration can also be presented to the Municipal Department of the Environment as proof of the regularization commitment made with COPASA.

Along with the Declaration, the entrepreneur receives Technical Standard T.187 and the Terms of Reference, which guide the preparation of the Technical Project.

5. Technical Project – Part A
The presentation of Part A must be made within 60 days of the project's adherence to PRECEND and must follow the Terms of Reference, which include:

• Project details and description of activities;
• Flowchart of the production processes, identifying the points where effluents are generated;
• Water balance (water consumption and effluent flow rates);
• Plans and layouts of sewage networks, from the generating sources to the final destination in the sewer system, distinguishing between domestic wastewater, non-domestic wastewater, and rainwater;
• Sampling plan, including collection points, frequency, sample type (simple or composite), and parameters to be analyzed.

Once completed, Part A is forwarded to COPASA for analysis and approval.

6. Technical Project – Part B
After Part A is approved, the entrepreneur has a deadline to submit Part B. According to the program's guidelines, this deadline is 60 days. Part B contains:

• the analytical results of the sampling plan, compared to the limits of Standard T.187;
• the necessary adjustments to the internal sewage systems;
• The design of the pre-treatment system, when necessary, with a descriptive and calculation report;
• the schedule for the execution of the works and adaptations;
• The self-monitoring plan, with parameters, data collection frequency, and report delivery periodicity.

7. Approval of the Technical Project
COPASA analyzes the Technical Project and issues its opinion. With the approval of Part B, the process moves on to the formalization of the contract.

8. Contract signing and implementation of adjustments
With Part B approved, the Service Provision Contract for the Reception and Treatment of Domestic and Non-Domestic Wastewater is signed.

If works or adjustments are necessary, the entrepreneur must carry them out according to the approved schedule. From then on, they must comply with self-monitoring: periodic collection and analysis of effluents, with reports sent to COPASA within the deadlines stipulated in the contract.

What are the consequences of non-compliance with PRECEND?

Like any contractual instrument, PRECEND provides for penalties and fines in case of non-compliance. When an irregularity occurs, COPASA notifies the user and guarantees a period for defense before applying sanctions.

The following are considered non-conformities subject to fines or penalties:

• do not deliver self-monitoring reports, or submitting them incomplete or late;
• submit reports with results above the limits established by COPASA Technical Standard T.187/6;
• fail to comply with any other obligation. as stipulated in the contract, such as the approved schedule of adjustments.

In addition to contractual penalties, irregular discharge can lead to liability in administrative, civil, and criminal spheres. The legal basis includes Law No. 9.605/1998 (Environmental Crimes Law) and state environmental legislation. The company is also exposed to reputational damage and difficulties in obtaining licenses and permits.

More than just meeting legal requirements and avoiding penalties, PRECEND is a management tool for regulating and controlling non-domestic wastewater.

By joining the program, the company learns about the characteristics of its effluents, identifies the necessary adjustments, and defines, together with COPASA, the conditions for the discharge into the sewer system to occur safely and in a controlled manner.

Compliance with PRECEND contributes to the regularization of the project, the protection of the sewage network, the proper functioning of treatment plants, and the preservation of water resources.

References

• BRAZIL. Law No. 9,605, of February 12, 1998. Provides for criminal and administrative sanctions arising from conduct and activities harmful to the environment. Available at: planalto.gov.br.
• BRAZIL. Law No. 11,445, of January 5, 2007. Establishes national guidelines for basic sanitation. Available at: planalto.gov.br.
• BRAZIL. Law No. 14,026, of July 15, 2020. Updates the legal framework for basic sanitation. Available at: planalto.gov.br.
• NATIONAL ENVIRONMENT COUNCIL (CONAMA). Resolution No. 430, of May 13, 2011. Establishes the conditions and standards for effluent discharge.
• COPAM/CERH-MG. Joint Normative Deliberation No. 8, of November 21, 2022. Establishes the classification of water bodies and the conditions and standards for effluent discharge in Minas Gerais.
• ARSAE-MG. Resolution No. 040, of October 3, 2013. Establishes the general conditions for the provision of water supply and sewage services.
• ARSAE-MG. Resolution No. 117, of November 20, 2018. Approves COPASA Technical Standard T.187/6.
• COPASA. Technical Standard T.187/6 – Discharge of Non-Domestic Effluents into the COPASA MG Sanitary Sewer System. Available at: copasa.com.br.
• COPASA. PRECEND Program – Program for Receiving and Controlling Non-Domestic Effluents. Presentation to the Municipality of Belo Horizonte, Apr. 2023. Available at: prefeitura.pbh.gov.br.
• MINAS AGENCY. Research evaluates the impact of non-domestic wastewater discharge on the sewage system. Available at: agenciaminas.mg.gov.br.
• ABNT. NBR 9898: Preservation and sampling techniques for liquid effluents and receiving bodies. Rio de Janeiro: ABNT, 1987.
• APHA; AWWA; WEF. Standard Methods for the Examination of Water and Wastewater. Washington, DC: APHA.