Wiertsema & Partners B.V. is an engineering company founded in 1979 and specialised in : • geotechnical site investigations; • geotechnical laboratory testing; • geotechnical consultancy; • geohydrological field studies and consultancy; • geotechnical and hydrogeological monitoring; • special tests (pile driving tests, plate loading tests, vibration tests); • environmental soil and groundwater exploration and consultancy. Wiertsema & Partners strives for a controlled sustainable growth in revenue and net result. In order to reach this goal we strive for an optimised and balanced synergy between the various activities and delivering added value to our clients by a combination of specialised staff, state of the art technologies and quality services. Wiertsema & Partner has developed over the years into one of the larger Dutch geotechnical consulting companies. In november 2007 we extended our activities with the specialised offshore company Marine Sampling Holland, which operates world wide. In 2016 SEMASO is founded as a sister company in close cooperation with Ravensrodd Consultants Ltd. SEMASO is specialised in sediment management solutions for rivers, estuaries and marine coastal environments around the world.