To destroy the canisters around a given camp, you must speak to Oona Wran inside the camps Alpha, Beta, Gamma and Delta. He would give you the four quest "Destroy Canisters Around Camp Alpha", "Destroy Canisters Around Camp Beta", "Destroy Canisters Around Camp Gamma", "Destroy Canisters Around Camp Delta".
You must complete the quota for Alpha, Beta, Gamma and Delta to complete the collection.