Tuhia he tomokanga mo tenei whitianga - I muri i te wikitoria i te mētara koura me te mētara hiriwa i te European Junior Swimming Championships 1998 i Antwerp i hanga e ia tana tuatahi o te ao i te 1999 FINA Short Course World Championships i Hong Kong. I wini tonu a Groot i tana mētara tuatahi o te ao, he hiriwa, i te reanga 4 × 100 m freestyle me Thamar Henneken, Wilma van Hofwegen me Inge de Bruijn. Ko ia anake i mutu i te 14th i te 100 m butterfly. I etahi marama i muri mai ka whakataetae ia i te 1999 European Aquatics Championships
i roto i Istanbul. I roto i te 50 m butterfly i wikitoria ia i tana mētara takitahi tuatahi, i te 17 o ona tau, ka eke ki te tuatoru o nga waahi i muri i a Anna-Karin Kammerling me Johanna Sjöberg. I tae ano a Chantal ki te whakamutunga o te 50 mita freestyle ka mutu te 7th. I roto i te 4 × 100 m freestyle i mutu ia i te tuawha me te tiima.