31.37. In the depollution attestation, the Minister may, for each municipal wastewater treatment works, set down contaminant discharge standards which differ from those referred to in paragraph 3 of section 31.34, if the latter standards do not adequately ensure that the environment affected by the municipal wastewater treatment works is suitable for the normal development of human beings and plant and animal life, or do not adequately protect human beings and animal and plant life from unacceptable risks imputable to the acute or chronic toxicity of any contaminant or to its carcinogenic, mutagenic, teratogenic or synergistic effects.