The relevant market segment defines the products that could potentially beinvolved in a product substitution. This is identified in the key phases where customer segments and niche markets are studied. In some cases, the product or product alternatives to be included may be indicated in advance, in which case they contribute to defining the relevant product properties. With regard to public applications, which typically aim to influence a predetermined market, the study should focus on products that are (expected to be) available in that market. For example:
- To determine ecological labeling criteria for a product, a study should include a representative selection of product alternatives that can be interchanged in the relevant market segment. A narrower selection would be perceived as unfair to the excluded alternatives and would not reflect the real potential for environmental improvement. A broader selection would be seen as suggesting irrelevant alternatives and therefore an unfair comparison.
- An internal company study on the same product may limit itself to studying different alternatives within the company's own product range or that of its closest competitors without causing such problems. However, since even internal company studies should seek to reflect the actual consequences of decisions, it is advisable to include all envisaged product alternatives.
Application Example - Purification of Drinking Water
Context and Background
Filtration through biologically active sand filters is one of the most common purification processes for the production of drinking water. However, the contamination of source water with organic micropollutants such as pesticides, solvents, and pharmaceuticals often forces waterworks to either close extraction wells or further purify the water before distribution. In Denmark, contamination of aquifers by pesticides is one of the major issues in the drinking water sector. One possible solution to this problem is biological treatment through so-called "bioaugmentation" (for simplicity we will call it BA), which involves introducing organisms capable of degrading specific compounds into existing sand filters.
In a comparative LCA, bioaugmentation should be compared with functionally equivalent alternatives, taking into account the specific context of Denmark, where currently only groundwater resources are used to produce drinking water. We can identify the following alternatives that could compete with BA:
- Granular Activated Carbon Adsorption (GAC). It is a proven technology that involves passing water through a carbon filter where pollutants are adsorbed onto the porous surface.
In addition to solutions like GAC, the following alternatives can be considered:
- An alternative for a waterworks at risk of exceeding legal limits for micropollutants is to close contaminated wells and open new ones elsewhere with lower concentrations of micropollutants than the legal limits. In this scenario, the operation of the waterworks is not changed with any additional process, but involves dismantling existing wells and opening new ones.
- Another alternative to avoid directly addressing pollution is to seek new resources. This could be done through desalination of seawater. The issue with this option is that it is expensive compared to conventional production processes that use freshwater resources. This alternative would also involve dismantling the existing well and installing a new desalination plant.
All the mentioned alternatives serve the function of providing drinking water but are not entirely equivalent, as BA and GAC provide additional functions:
- They help extend the service life of existing groundwater extraction wells; well replacement and desalination do not allow this.
- BA and GAC remove pollution from groundwater, whereas well replacement and desalination do not address pollution.
To achieve full functional equivalence, the system boundaries for BA and GAC should be expanded to account for these additional functions. Another issue is that desalination "creates" new water resources, something none of the other options do.
References
Muñoz I, de Vries E, Wittebol J, Aamand J (2015) Prospective environmental and economic assessment for biotreatment of micropollutants in drinking water resources in Denmark. Water Science and Technology: Water Supply 15(6):1405-1413
Godskesen B., Hauschild M., Rygaard M., Zambrano K., Albrechtsen H.-J. (2013) Life-cycle and freshwater withdrawal impact assessment of water supply technologies. Water Research, 47 (7): 2363-2374
Next lesson - In-Depth Study "Definition of the Reference Flow"
