GENERAL INFORMATION
------------------

1. Dataset title:
KNOWLEDGE BASE OF NATURE-BASED SOLUTIONS FOR WASTEWATER TREATMENT AND STORMWATER MANAGEMENT


2. Authorship:

	Name: Josep Pueyo-Ros
	Institution: ICRA-CERCA; Universitat de Girona
	Email: jpueyo@icra.cat
	ORCID:  0000-0002-1236-5651

	Name: Joaquim Comas
	Institution: ICRA-CERCA; LEQUIA, Universitat de Girona
	Email: jcomas@icra.cat
	ORCID:  0000-0002-5692-0282

	Name: Massimiliano Rivas
	Institution: ICRA-CERCA; Universitat de Girona
	Email: mriva@icra.cat

	Name: Vicenç Acuña
	Institution: ICRA-CERCA; Universitat de Girona
	Email: vacuna@icra.cat
	ORCID:  0000-0002-4485-6703



DESCRIPTION
----------

1. Dataset language:
English


2. Abstract:
Three tables containing:
- A catalogue of nature-based solutions for wastewater treatment and stormwater management. For each solution there is information on its performance, types of water, cobenefits, barriers and cost.
- A list of scientific publications focused on one or several technologies of the above catalogue.
- For solutions for water treatment, a second table containing data about treatment performance extracted from previous scientific publications.

The most updated version of each table can be queried from https://snappapi-v2.icradev.cat/


3. Keywords: 
nature-based solutions; wastewater; stormwater


4. Date of data collection (dd/mm/yyyy - dd/mm/yyyy):
01/01/1973 - 30/11/2023

5. Publication Date (dd/mm/yyyy):
03-10-2024


6. Grant information:

	Grant Agency: European Commission
	Grant Number: 101003527

	Grant Agency: Science for Nature and People Partnership
	Grant Number: --

	Grant Agency: Departament d'Economia i Coneixement, Generalitat de Catalunya
	Grant Number: ICRA-ENV 2021 SGR 01282
	
	Grant Agency: Departament d'Economia i Coneixement, Generalitat de Catalunya
	Grant Number: ICRA-TiA 2021 SGR 01283


7. Geographical location/s of data collection:
Worldwide



ACCESS INFORMATION
------------------------

1. Creative Commons License of the dataset:
CC-0


2. Dataset DOI:
10.5281/zenodo.10401963


3. Related publication:


4. Link to related datasets:
	DOI/URL: https://snappapi-v2.icradev.cat/



VERSIONING AND PROVENANCE
---------------

1. Last modification date:
15-12-2023 


2. Were data derived from another source?:
No 


3. Additional related data not included in this dataset:



METHODOLOGICAL INFORMATION
-----------------------
The construction of the knowledge base within MULTISOURCE involved three distinct stages. These stages are delineated as follows:

1. Upgrade of the legacy from the SNAPP Project: The initial stage of knowledge base development is inherited from the SNAPP project “Guidance on evidence based practices for improved sanitation, water security and ecological health, with a focus on nature-based solutions“. This project was international and funded by the National Center for Ecological Analysis and Synthesis (NCEAS, UC Santa Barbara).

2. Addition of ENTS from MULTISOURCE Pilots: The second stage incorporates information from the MULTISOURCE pilots, expanding the scope of the knowledge base by including enhanced natural treatment systems.

3. Inclusion of Nature-Based Solutions for Stormwater Management: The third and final stage integrates nature-based solutions specifically tailored for stormwater management into the knowledge base.

SNAPP PROJECT

The SNAPP project played a pivotal role in establishing the foundation for the knowledge base within MULTISOURCE. The development of this knowledge base occurred through a series of elicitation workshops, primarily employing the IDEA protocol (Hemming et al., 2018) – a modified Delphi method. The workshops, conducted in Santa Barbara (22-24 May 2018), Vienna (Feb 11th, 2019) and Girona (Nov 8th, 2019), aimed to harness expert knowledge on the most suitable Nature-Based Solutions (NBS) for diverse socio-environmental contexts and needs. These workshops involved more than 40 experts worldwide, covering international representation (America, Europe, Asia and Africa) and expertise in all types of NBS.

Workshop Methodology:

During the workshops, more than international experts, covering international representation (America, Europe, Asia and Africa) and expertise in all types of NBS, engaged in a structured process. Firstly, they collaboratively identified nine major types of NBS and 26 associated sub-types, encompassing different varieties and combinations. Subsequently, participants addressed several key aspects to define the decision-making table.

Key Workshop Topics:

- NBS Characteristics: Participants detailed the characteristics of NBS for domestic wastewater treatment, considering various sub-types and their applicability.
- Wastewater Types and Treatment Targets: Discussions covered the types of wastewaters to be treated, main treatment targets, common climate categories, and categories of co-benefits.
- Pollutant Removal and Spatial Scale: For each NBS, experts assessed its capacity to treat different types of domestic wastewater and targeted pollutants. They also determined the spatial scale for installation, distinguishing between household/building and community-scale.
- Surface Requirements: Participants defined the required surface area for each NBS to treat one population equivalent under different climates (square meter per PE ratio).
- Technical Requirements: Consideration was given to whether each NBS requires external energy, with responses categorized as yes or no.
- Labor, Skill Requirements, and Biohazard Level: Discussions encompassed the labour and skill requirements for each NBS, along with categorizing associated biohazard levels as low (L), medium (M), or high (H).
- Co-Benefits: Experts evaluated the levels of various co-benefits associated with each NBS, including biodiversity (fauna and flora), temperature regulation, flood mitigation, storm peak mitigation, carbon sequestration, biomass production, aesthetic value, recreation, pollination, food source, water reuse, and biosolids provisioning. The levels for the cobenefits were defined in a qualitative scale of none (N), low (L), medium (M) and high (H).

This comprehensive approach ensured that the knowledge base derived from the SNAPP project incorporated expert insights on diverse dimensions of NBS.

Notably, a modification to the knowledge base structure was made during the first annual meeting of MULTISOURCE in Lyon on June 27th, 2022. There, in a workshop dedicated to co-designing the workflow of the technology selection tool, a decision was reached to incorporate the design or recommended organic loading rate for all NBS technologies (in grams of BOD per square meter). Since these values was not provided by the experts, it was calculated for existing technologies by dividing 60 by the square meter per person equivalent (PE) ratio. This assumption was based on the idea that one PE produces 60 grams of BOD per day  .

INTEGRATION OF ENHANCE NATURAL TREATMENT SYSTEMS FROM MULTISOURCE PILOTS

The second stage in building the knowledge base involved the inclusion of the innovative NBS (or enhanced natural treatment systems, ENTS) studied in the MULTISOURCE pilots into the roster of available technologies. The gathering of the data and knowledge for this integration took place during a workshop held at the second annual meeting of the MULTISOURCE project in Leipzig on June 5th, 2023.
The workshop consisted of two rounds. In the initial round, all project partners were tasked with providing data for all pilots, along with indicating their confidence level in supplying this information. This approach mirrored the knowledge base structure established during the SNAPP project. 

In the second round, MULTISOURCE partners were organized by pilots, collaborating to achieve consensus on the data for their respective pilot projects (i.e. responsible partners for one pilot worked out consensus for only the ENTS of that pilot). All collected data were summarized and weighted based on the confidence levels reported by users. The workshop aimed to reach a consensus decision, ensuring the integration of pilot data into the knowledge base.

INCLUSION OF NATURE-BASED SOLUTIONS FOR STORMWATER MANAGEMENT

The SNAPP project did not encompass technologies for stormwater management (SWM). Therefore, the first step in including SWM was to establish a structured framework for the knowledge base. All existing fields related to co-benefits and barriers in the knowledge base were retained, and new values concerning the water scenario were collaboratively defined with WP5 to ensure seamless interaction with the tools developed in that work package.

Structural enhancements:

1. Introduction of New Water Types: Two new water types, rainwater and runoff, were introduced. Notably, runoff water requires some form of treatment before infiltration or release into the environment.
2. Assimilation of Combined Sewer Overflow (CSO) Technologies: Previously to the consideration of SWM, three technologies were designated for combined sewer overflow (CSO) discharge. These technologies were assimilated into the SWM module. A field labelled “module” was introduced to differentiate between technologies for water treatment and those for SWM.
3. Additional Fields for SWM Technologies: To model the surface required by SWM technologies, new fields were added, including infiltration (yes or no), storage capacity (m3/m3), and depth or height of the technology (m).
Data Collection and Sources: The data collection for SWM technologies primarily relied on grey literature combined with expert knowledge. 

Desk work, as opposed to elicitation workshops, was the primary method for data collection. The main information source was Woods Ballard et al. (2015) by CIRIA.

Review and Validation: Following the collection and curation of all data, it underwent a review process conducted by WP5 partners (UFZ and INSA) to ensure accuracy and completeness.

COLLECTION OF SCIENTIFIC PUBLICATIONS

Similar to the knowledge base, the collection of scientific publications underwent a two-stage process. The initial batch of publications was collated during the SNAPP project, focusing solely on water treatment technologies appearing on scientific journal papers (until 2019). Subsequently, within the MULTISOURCE project, the database was updated to include new scientific publications for water treatment (2020-2022), data from grey literature and expanded to encompass stormwater management (SWM) technologies.

First Stage: SNAPP Project Publications (Water Treatment).

Scientific studies pertaining to the utilization of Nature-Based Solutions (NBS) in domestic wastewater systems constituted the first stage of publication collection. Using the Web-of-Science database, a comprehensive search was conducted on May 23rd, 2019, encompassing studies published in any year. Nine distinct searches, one for each type of NBS, were executed, with search terms strategically chosen to ensure the inclusion of all potentially relevant studies. Eligibility criteria were established, requiring full-text availability, English language, exclusion of laboratory case studies, prioritization of full-scale or pilot-scale studies, exclusion of reviews, and the inclusion of articles providing information on at least three selected variables characterizing NBS.

Upon identifying potentially relevant articles, a meticulous selection process ensued. To ensure consistent choices, 30% of the articles underwent a dual review (title and abstract) by two researchers. The final inclusion in the database was contingent on meeting the eligibility criteria outlined above.

During the abstract review, reviewers introduced additional fields for each case study in the spreadsheet. These fields, organized into six domains—removal efficiencies, water sources/types, sustainability indicators, co-benefits, elements of the urban wastewater system, and design and operational settings (see Figure 1)—were filled in by extracting information from the abstract or, if necessary, by downloading and reviewing the full text of the article. This information is used for the NBS technology selection to train regression models that estimate the surface required for a specific technology and specific water characteristics.

Second stage: Additional data inclusion.

Within the MULTISOURCE project, the same methodological approach utilized during the SNAPP project was applied to update the database for water treatment technologies, extending the data collection until the year 2022.

In the context of stormwater management (SWM) technologies, the objective was to compile a list of pertinent publications for each technology, facilitating future reference for tool users. As the technology selection tool does not rely on data-driven models to estimate the surface of SWM technologies, there was no additional data sought within the gathered publications.

Search Strategy: To gather relevant publications, the SCOPUS database was employed. Specific queries were crafted for each technology, combining the technology name with “runoff” or “stormwater” in the title or abstract.

Publication Curation: The list of obtained references underwent careful curation to exclude publications not directly related to the technology or its ability to manage stormwater. This curation process relied on a filter based on the title and abstract.

This focused approach ensures that the compiled list of publications for SWM technologies remains relevant and directly applicable for user consultation within the technology selection tool.


1. Description of the methods used to collect and generate the data:


2. Data processing methods:

3. Software or instruments needed to interpret the data:
CSV editor.

4. Information about instruments, calibration and standards:

5. Environmental or experimental conditions:

6. Quality-assurance procedures performed on the data:


FILE OVERVIEW
----------------------

1. Explain the file naming conversion, if applicable:



2. File list:

	File name: NBS_catalogue.csv
	Description: Catalogue of NBS with characteristics.

	File name: sci_publications.csv
	Description: List of scientific publications focused on one or several technologies included in the catalogue

	File name_ sci_publications_treatment_details.csv
	Description: Data of treatment performance of scientific publications from sci_publications.csv exclusive for wastewater treatment 	technologies.


3. Relationship between files:
NBS_catalogue.id = sci_publications.sub_type
sci_publications.id = sci_publications_treatment_details.id_sci_publication

4. File format:
CSV


5. If the dataset includes multiple files, specify the directory structure and relationships between the files:



SPECIFIC INFORMATION FOR TABULAR ATA
-------------------------------------------

1. Name file:
NBS_catalogue

2. Number of rows and columns: 
53:58


3. Variables list:

4. Codes or symbols for missing data:

	Code or symbol: NA
	Definition: Missing value

1. Name file:
sci_publications.csv

2. Number of rows and columns: 
883:15


3. Variables list:

4. Codes or symbols for missing data:

	Code or symbol: null
	Definition: Missing value

1. Name file:
sci_publications_treatment_details.csv

2. Number of rows and columns: 
646:35


3. Variables list:

4. Codes or symbols for missing data:

	Code or symbol: null
	Definition: Missing value
