For use when injecting remediation liquid via an injection-well into contaminated groundwater, in the ground. The injection equipment includes a pulse-generator, which has an upstream chamber and a downstream chamber, linked by a pulse-conduit and a bypass conduit. The pulse-conduit includes a pulse-port, which opens and closes cyclically. The pulse-port is formed by the interaction of two apertures, one in the motorised rotor, the other in the stator. The rotor and stator may be formed as two facing plates held slightly apart, or as two cylinders one inside the other. The pulse-generator is located at the ground surface and can be adjusted as to pulse frequency, pulse amplitude, pulse rise-time, and as the the differential pressure between the upstream-chamber and the downstream chamber.