While the high costs of the construction and maintenance of modern sewage-treatment plants are an important constraint, it should be noted that cheaper biological treatment methods exist that are especially suited to tropical climates.
L &apos; importance des coûts de construction et d &apos; entretien des stations d &apos; épuration modernes des eaux usées constitue un obstacle de taille mais il convient de noter qu &apos; il existe des méthodes d &apos; épuration biologique moins onéreuses particulièrement adaptées aux climats tropicaux.