Colorado authorities are cracking down on rental homes where a huge number of marijuana plants are being grown illegally.

In one instance, a tenant tapped into the plumbing so he could set up an irrigation system, ripped out the carpet, installed an air conditioner, put a separate furnace in, removed part of a staircase and dug a trench from the yard to a nearby power pole to bypass the grid—allowing him to steal $8,000 in electricity over five months.

DEA agents, attorneys and real estate experts told KKTV 11 News to put specific language in leases stating no agriculture can be grown on the property and that inspections be allowed at least two to four times a year.

Property manager Victoria Baker says her leases have grown from four to more than 20 pages long, making it clear to tenants that they're not allowed to use or grow medicinal or recreational marijuana.

The station reports that while transformer overloads can be caused by other things, Colorado Springs Utilities say there's been a 400% increase in them from 2014 to 2015. Many of the illegal growers are coming from the East Coast, as they can grow the pot cheaply in Colorado and make double or triple selling it back home. [KKTV]