Kammala jumla mai zuwa: Bayan lashe lambar zinare da lambar azurfa a gasar zakarun Turai ta 1998 a Antwerp ta fara fitowa a gasar zakarun duniya ta 1999 a Hong Kong. Groot nan da nan ta lashe lambar yabo ta farko ta kasa da kasa, azurfa, a tseren tseren 4 × 100 m tare da Thamar Henneken, Wilma van Hofwegen da Inge de Bruijn. Da kanta ta gama 14th a cikin 100 m butterfly. Bayan 'yan watanni sai ta yi gasa a gasar
1999 Gasar Wasannin Ruwa ta Turai a Istanbul. A cikin 50 m butterfly ta lashe lambar yabo ta farko, a lokacin da take da shekaru 17, inda ta kai matsayi na uku a bayan Anna-Karin Kammerling da Johanna Sjöberg. Chantal kuma ya kai wasan karshe na 50 m freestyle ya ƙare 7th. A cikin tseren 4 × 100 m kyauta ta gama na huɗu tare da ƙungiyar.