NY Real Property Law 235-b (warranty of habitability) provides that: "In every written or oral lease or rental agreement for residential premises the landlord or lessor shall be deemed to covenant and warrant that the premises so leased or rented and all areas used in connection therewith in common with other tenants or residents are fit for human habitation and for the uses reasonably intended by the parties and that the occupants of such premises shall not be subjected to any conditions which would be dangerous, hazardous or detrimental to their life, health or safety".Plumbing leaks & flooding conditions have been found by NY courts to be a breach of the warranty of habitability by the landlord. A residential tenant may be awarded damages, if the court finds that the landlord breached the warranty of habitability. Damages for a breach of the warranty of habitability (known as a rent abatement) are determined by a court's finding (calculation) of the difference between the rent under the lease & the rental value during the time the conditions existed in the premises.Separate & distinct from a rent abatement, a tenant may also claim consequential damages (including property damage), but must do so in a separate action, not as part of the tenant's claims in a landlord-tenant proceeding.It is important to document the conditions in the premises related to the septic line, as well as any expenses in connection with the septic line blockage. In addition to documents, you can also include dated photographs & video if the court determines that it satisfies the rules of evidence. If the landlord starts a nonpayment case in landlord-tenant part of local court, you may file a counterclaim seeking an abatement of rent based upon the landlord's breach of the warranty of habitability. After a trial, the court will decide the respective claims raised by the landlord & tenant.