For the period 2020–2023, approximately 464,000 m sewer must be cleaned and inspected collectively for the 7 West Frisian municipalities. Each municipality orders separately.

Quantities are per year:

- approx. 6,800 units of the municipality of Stede Broec,

- approx. 5,800 units of the Enkhuizen municipality (and approx. 1 000 m line troughs),

- 6,600 swirl units in the municipality of Drechterland.

A total of around 19 200 pieces of swirl.

Quantities are per year:

- around 8,000 units of the Koggenland municipality,

- approx. 4 700 units of swirls in the municipality of Opmeer,

- approx. 17,500 swirls in the municipality of Medemblik (approx. 80 m line troughs).

A total of around 30 200 pieces of swirl.

Quantities per year: approx. 34,500 pieces of gullies (approx. 1,250 m line troughs).