Short abstract:

We all want clean water, but what is clean water? In this paper, I follow water engineers in the Netherlands whose job it is to ensure ecologically ‘clean water’. By analyzing their efforts to determine whether surface water is clean, I argue that what ‘clean water’ is comes in different versions.

Long abstract:

When it comes to surface water protection, clean is not simply a ‘matter of fact’ but a situated appreciation, a diagnosis: it's about determining whether the water is clean enough for the organisms dependent on it. By following engineers on their quest to find good ways to determine whether this or that water is ‘clean enough’, I've learned that what clean water is, varies according to the type of water being measured (effluent or surface water), the entities under examination (chemical substances or biological responses in organisms), the methodology employed (quantifying different biological entities or calculating the toxic pressure of biochemical reactions), and the purpose of the measurement (to optimize the local ecosystem or to meet standards that can travel). For water engineers, navigating these diverse versions of clean poses a challenge that surpasses mere assessment of water cleanliness; it entails the intricate task of coordinating these versions of clean, to pinpoint where and how improvement measures should be implemented to enhance ecological cleanliness. While this presents a complex and indeterminate problem space, for water engineers, failing to address its challenges, however fragmented, leads to dirty water one way or another. This prompts STS scholars to consider which stories to tell and how to tell them in ways that contribute to fostering good care for water and its troubles, without restoring fragmented knowledge and valuing practices into coherent problem-solving accounts.