California Code, Civil Code - CIV § 1954.202

(a) “Billing agent” means a person or entity who contracts to provide submetering services to a landlord, including billing.

(b) “Landlord” means an owner of residential rental property.  “Landlord” does not include a tenant who rents all or a portion of a dwelling unit to subtenants.  “Landlord” does not include a common interest development, as defined in Section 4100 of the Civil Code.

(c) “Property” means real property containing two or more dwelling units that is served by a single master meter.

(d) “Ratio utility billing system” means the allocation of water and sewer costs to tenants based on the square footage, occupancy, or other physical factors of a dwelling unit.

(e) “Rental agreement” includes a fixed-term lease.

(f) “Renting” includes leasing, whether on a periodic or fixed-term basis.

(g) “Submeter” means a device that measures water consumption of an individual rental unit within a multiunit residential structure or mixed-use residential and commercial structure, and that is owned and operated by the landlord of the structure or the landlord's agent.  As used in this section, “multiunit residential structure” and “mixed-use residential and commercial structure” mean real property containing two or more dwelling units.

(h) “Water service” includes any charges, whether presented for payment on local water purveyor bills, tax bills, or bills from other entities, related to water treatment, distribution, or usage, including, but not limited to, water, sewer, stormwater, and flood control.

(i) “Water purveyor” means a water purveyor as defined in Section 512 of the Water Code.