Sustainable basic sanitation systems. Types, techniques and examples

Sustainable sanitation systems

Have you ever wondered where all the effluent you generate in your home or workplace goes? What happens once you flush the "cistern" of your toilet? o Why are the systems of basic sanitation do they mix gray water with black water?

Probably not. And there is nothing wrong with that, since if you live in an environment where the systems work well, there is nothing that makes you question their operation.

I tend to think that that question is not a matter of public concern because the sanitation networks they are hidden from our eyes. They are infrastructures that circulate underground. And as the saying goes … Eyes that do not see, heart that does not feel!

But I tend to think that there is something more anthropological behind this. And it is that, culturally, we have a refusal to talk about our excreta and the different waste that we generate.

Regardless of this, the truth is that sanitation systems Conventional (which almost all of us know) have many deficiencies and limitations that make it impossible to think of them as the solution to global problems in water issues and sewerage.

They present serious problems both in their limited coverage capacity, their high economic cost for their implementation and maintenance, and the negative impacts on the environment.

It is also true that today, in the XXI century, almost 40% of the world population does not have access to systems and sanitary infrastructures Y drainage networks sure … can you believe it?

It is very likely that this crisis (like all of them) is due to many variables, but fundamentally to one: The technologies we are using to solve the problem.

Technological alternatives exist (they have always existed) and in today's article I want to present an alternative to face this crisis as well as techniques or types of sanitation environmental that must be executed.

What is sustainable sanitation

As a first instance we can say that the infrastructure ofsustainable sanitation aims to overcome the disadvantages of systems and approaches presented by conventional systems.

One of the key principles to understand the approach, perhaps is to understand and recognize human excreta not as a waste, but as a valuable resource that can be used and recycled.

We can see a general scheme of a comprehensive management system for ecological sanitation:

Establish networks of sustainable sewerage It is a work approach that involves the development and implementation of technologies aimed at preventing pollution of ecosystems, saving water and returning the nutrients contained in our excreta to terrestrial ecosystems in order to be used for agricultural production.

Characteristics

• Saving, reusing or recycling water.
• Separate and recycle: Separate excreta and waste and treat them independently. Never put them together !!!
• Return of the nutrients contained in our excreta (nitrogen, phosphorus and potassium) to the soil and use in agricultural production.
• Protection of human health, by preventing contamination of surface and underground water sources.
• Prevention of contamination of resources (physical, biotic and abiotic) and terrestrial and aquatic ecosystems.
• Do not exceed the carrying capacity of the ecosystems where it is inserted.

Any type of purification technology thus handled is considered a beneficial technology in favor of improving the sewerage and water treatment, that is, we are facing a environmental sanitation that respects the environment and is sustainable.

The next scheme on separation of flows and waste helps to generate a more efficient and sustainable structure where nutrients are re-incorporated (returned) to the soil.

Objectives of sanitation systems

1. An adequate purification system is vital for human health.

• Diarrhea kills 5,000 babies and children every day.
• Access to hygienic toilets can reduce these deaths by more than 30%, and hand washing by more than 40%.
• Intestinal helminths absorb about 1/3 of the food a child eats, and malnutrition is the cause of 50% of childhood illnesses.
• The combination of acute respiratory and diarrheal diseases makes inadequate sanitation and poor hygiene the main reason for infant deaths.

2. It generates economic benefits.

• People without toilets spend 30 min. diaries looking for one. A family of 6 people is equivalent to 21 hrs. non-productive a week. A health system for those families it would imply 1,000 hrs. per year to work, study, babysit, engage in collective tasks and rest.
• The improved one produces 9 dollars of benefit for every dollar spent
• The sewerage and hygiene are among the most cost-effective public health interventions
• With the reduction in childhood diarrhea, almost 200 million days of school attendance would be added per year.

3. Contributes to the dignity of people and social development.

• Every day, the human dignity of the 2.6 billion people who have to defecate in plastic bags or buckets, on train tracks or the gutters along the roads, is undermined.
• A toilet can accelerate social development:
  • Contributing towards gender equity.
  • Promoting social inclusion.
  • Increasing school attendance.
  • Developing community pride and social cohesion.
  • Contributing to the eradication of poverty

4. Purification protects the environment.

• Toilets, sanitary facilities, solid waste dumping and sewage water and rainwater drainage are essential requirements for clean and healthy environments, in addition to safeguarding environmental quality, especially that of water resources.
• A healthy living environment depends on efficient and hygienic sanitary facilities.
• Hygienic toilets help on the path to sustainable development in a powerful way.
• The reuse of waste brings many environmental and productive benefits (agro-sanitation)

5. Improving waste sewer systems is an achievable task

• The sewer systems for all it does not require huge sums of money or great scientific advances or knowledge.
• With only USD 10 billion a year (less than 1% of global military spending) we can safely increase coverage, and ten years later, everyone could use a toilet
• Some axes to reach it:
  • Job
  • Speak clear
  • Political leadership
  • Create demand for a Drainage network and satisfy her

In 2015, several member countries of the United Nations (UN) adopted a set of 17 global goals to eradicate poverty, protect the planet and ensure prosperity for all as part of a new sustainable development agenda.

Each goal has specific goals that must be achieved by 2030. To achieve them, everyone has to do their part: governments, the private sector, civil society, and people like you and me.

Objective number 6 refers to Clean Water and Sanitation. And its goals are:

• By 2030, achieve universal and equitable access to drinking water, at an affordable price for all

• By 2030, achieve equitable access to services from a Drainage network and adequate hygiene for all and end open defecation, paying particular attention to the needs of women and girls and people in vulnerable situations.

• By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing the discharge of hazardous materials and chemicals, halving the percentage of untreated wastewater, and a substantial increase recycling and safe reuse worldwide.

• By 2030, substantially increase the efficient use of water resources in all sectors and ensure the sustainability of freshwater extraction and supply to address water scarcity and substantially reduce the number of people suffering from water scarcity .

• By 2030, implement integrated water resources management at all levels, including through cross-border cooperation, as appropriate.

• By 2022, protect and restore water-related ecosystems, including forests, mountains, wetlands, rivers, aquifers, and lakes.

• By 2030, expand international cooperation and support to developing countries for capacity building in activities and programs related to water and a healthy network, including water collection and storage, desalination, efficient use of resources water, wastewater treatment and recycling and reuse technologies.

• Support and strengthen the participation of local communities in improving the water and sewerage management.

Why is environmental sanitation important?

The current global situation regarding access to drinking water and the different purification systems is critical and with it the lives of many people in the world are in crisis in the face of the possibility of accessing the environmental sanitation or sustainable.

Here are some uncomfortable data that help us understand the situation in the world:

• Currently 663 million people in the world do not have access to drinking water sources.
• At least 1.8 billion people in the world use a source of drinking water that is contaminated with fecal matter
• Water scarcity affects more than 40% of the world's population, and this number is expected to increase. More than 1.7 billion people currently live in river basins where water consumption exceeds recharge
• Currently, 2.4 billion people lack access to basic sanitation services, such as toilets or latrines. About 1 billion of them practice open defecation.
• More than 80% of wastewater resulting from human activities is discharged into rivers or the sea without any type of treatment.
• Every day, about 1,000 children die from preventable diarrheal diseases related to lack of water and a Sanitary sewer.

Disadvantages basic sanitation

As we have stated in the introduction, the basic sanitation system conventional, those that we all know, you present several problems, like this … What comparative disadvantages are there?

• I dare say that the main problem and disadvantage is in its starting point: since these systems consider excreta as a waste that must be eliminated.
• And from that premise, what they develop is a "Linear flow system" in which different wastewater (gray and black) is mixed with drinking water, generating a LARGE volume of a highly contaminated flow.
• A flow for which you then have to implement sophisticated and expensive Treatment plants in order to purify the previously contaminated flow.
• These technologies have something of nonsense. If you think about it, what they do is generate a highly contaminated flow and then purify it.
• Using common sense, wouldn't it be more logical to implement technologies that do not generate thathighly polluted flow, and thus avoid all the costs and negative impacts that this generates?
• These types of technologies, due to their high cost of implementation and maintenance, have worked well in some "developed" countries, but their direct transfer to developing countries has not been successful.
• On the contrary, they have exacerbated the health crisis since they do not have the human and financial resources for their correct planning, implementation, operation and maintenance.

Problems of conventional water and purification systems

• High investment costs, energy and impact on ecosystems.
• High consumption and waste of good quality water.
• Pollution of surface waters by pathogens.
• Loss for the cycle of agricultural ecosystems of the nutrients contained in excreta and waste.
• Agricultural land degradation and eutrophication of the water cycle.
• They have proven unsustainable and socially exclusive.
• They present geographic and demographic limitations for their implementation.

This type of method also requires centralized treatment plants, which have several disadvantages.

It requires high costs for its construction, operation, energy consumption, chemicals, requirements of qualified technical professionals, as well as the loss of many nutrients in the air or in landfills.

The conventional wastewater treatment methods They have great potential to be optimized and more sustainable by reducing water use and improving the recovery and reuse of energy and nutrients. (See also article of interest sustainable urban planning of water where some sanitation techniques of interest)

On the streets we can see how inefficient can be the sanitary sewer techniques and conventional rainwater in terms of wasting resources and excessive pollution of clean water. With the aggravation that in many countries you are waste treatment plants they malfunction, leading to contamination of soils and bodies of water.

Methodology to be met for its implementation

So that a health system coherent that can be considered sustainable must contemplate in all its stages: collection, treatment and its subsequent use, the following dimensions:

1. Dede protects and promote people's health.
2. It must be a technically viable infrastructure.
3. It must be an economically sustainable and socially non-exclusive system.
4. It must have cultural, social and institutional acceptance.
5. Dede protect the environment and preserve natural resources.

What are the technological components

In the following diagram we can see possible technical components for the implementation of the environmental sanitation techniques and the water sanitation methods more widespread:

Another of the great differences that exists is that they are decentralized. This means that they bet on "Collection, treatment and use stations" more than by large centralized treatment plants (like conventional systems).

Sustainable sanitation types

• Composting systems.
• Ecological Dry Baths.
• Re-use of treated faeces in agricultural systems.
• Re-use of treated urine as a bio-fertilizer in agricultural production.
• Artificial wetland systems for wastewater treatment.
• Gray water filters.
• Rainwater harvesting systems.
• Implantation of bio-digesters.

Later we will see some examples of environmental sanitation so that you have perspective of their techniques …

How they are executed

Here comes into play what is known as "Close the cycle of sanitation" which refers to closing the cycle of the nutrients contained in human excreta. Today, systems of sanitation network Conventionals break this natural cycle, since the nutrients contained in the food we eat (once excreted) are sent to aquatic ecosystems.

If you think about it, what all other species do: they re-incorporate their excreta into terrestrial ecosystems. To the earth what is of the earth …

Close the cycle sustainable sanitation It involves returning the nutrients contained in human excreta to terrestrial ecosystems in a safe and treated way.In this way, the natural cycle of nutrients is ensured and maintained.

The following diagram shows in a simple way a example of environmental sanitation how the separation, treatment and reuse of our waste can be in balance with the natural cycle of nutrients.

Example of social inclusion

This is a good example of how a project can improve people's quality of life and generate local micro-enterprises around the world of sanitation. A project developed in the peri-urban areas of Cochabamba, Bolivia.

One of the objectives was the creation and promotion of local companies that provide services for the construction, operation and maintenance of Dry Ecological Bathrooms (BES).

If you are interested in learning more about this experience and downloading a project report and infographic, you can do it from here.

Technical and practical example

In this case, as examples of sustainable sanitation and practical I want to leave an experience that I had the opportunity to know and personally evaluate was the implementation of a domestic wastewater treatment system with a system of Subsurface Flow Artificial Wetlands (HFSS).

The pilot experience was developed in a neighborhood on the urban outskirts of Montevideo, Uruguay. The system is designed to cover 61 homes, 479 people, with a maximum potential of 540 people.

The system has a 3-phase treatment system:

• Primary treatment based on septic chambers.
• Secondary treatment based on anaerobic filters.
• Tertiary treatment based on 4 subsurface flow constructed wetlands (HFSS).

Each wetland has a surface area of 128 m2 (8 × 16 meters). Which adds up to a total of 512 m2 of constructed wetlands.

A pilot experience that was not without its problems. One of the main problems identified was the lack of preparation of the Municipal technicians for the subsequent (and necessary) monitoring andmaintenance of the constructed wetland system.

As a consequence of this, 2 years after the operation of the system, they presented areas of water saturation, mainly due to the fact that the inlet and outlet pipes of the wetland liquids had become "clogged". This was obviously due to the lack of monitoring and maintenance of the system.

A second problem detected was the low participation / inclusion of the community in this pilot project. In this kind of sustainable sanitation projects technology transfer to the community involved is key.

As a consequence of this, people did not know very well what artificial wetlands were, they did not know how to take care of them or how to detect faults in their operation.

It could be seen that in some areas the wetland was used as a children's play area and micro-garbage dumps were found in others.

Technology transfer and participation with the community can avoid this type of practice, and most importantly, it gives people the ability to monitor the system and communicate any eventual failure to the authorities.

Despite this, the system has been successful and is proof of how a vulnerable community, without access to conventional sanitation networks, can generate decentralized solutions that improve their health and that of the environment in which they live.

Supplementary reference information

If you would like to know the work of different organizations in the world that work and promote a sustainable drainage network. I invite you to review the following links where you can also find different guides and manuals reference:

• Guide for a Comprehensive Ecological Sanitation System in Periurban and Rural Areas EI ECODESS from HERE.
• Sarar Transformación (Mexico) www.sarar-t.org
• EcoSanRes (Sweden) www.ecosanres.org
• Stockholm Environment Institute (Sweden) www.sei-international.org
• World Toilet (International) www.worldtoilet.org/
• An excellent guidance document Compendium Sanitation Systems HERE

I also take this opportunity to invite you to review and learn about my AboutHaus Blog, and read other articles related to architecture, house designs, energy efficiency, etc.

An architecture blog where I help people who are starting to build their house to make good decisions and find a quality design for the house of their dreams.

Now tell me … Did you already know the Sustainable Sanitation approach? How is the current situation of access and sanitation coverage in the country where you live?

I invite you to comment and share your opinion, thus we enrich the discussion between all. We wait for you below, in the comment box :)

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