It's easy, just needs working through. We have, say, 300,000 Asian/Afghan/Iraqi/Somalian (etc etc) workers to enter Britain. They need somewhere to live, so maybe chop down Thetford Forest, or kick the disgusting MOD off Salisbury Plain, and set them building. At each weeks' end they will need payment, and this one is a little more difficult, but I suggest that a man from the council or the gumment turns up with loads of cash which they can then spend in all the local shops they will have built. No worries about staffing those shops, just ship the relatives in from Asia/Afghanistan/Somalia etc etc. Everybody will be so content that there will be no crime, no local resentment, it will all be lovely.
p.s. no need for sewage farms, just crap in the surrounding fields, the ones just outside the ones you have built on.