... company is available for you 24 hours a day, every day. Day or night, weekend or weekday? You can always count on Optimaal Rioolservice! We operate in Almere, Amersfoort, Amsterdam, Amstelveen, Beverwijk, Bilthoven, Breukelen, Bussum, De Bilt, Haarlem, Hilversum, Houten, IJsselstein, Maarssen, Naarden, Nieuwegein, Rotterdam, Utrecht, Weesp, Zeewolde, Zeist, Haarlem.