Planning a home addition, new construction project, or major renovation in Queens, NY? Before construction can move forward, you may need approval from the New York City Department of Environmental Protection (DEP) to confirm that the property's sewer system can accommodate the proposed development.

For property owners, these requirements can seem complicated, especially when coordinating construction plans, building permits, and drainage requirements.

1. What Is NYC DEP Sewer Certification?

• NYC DEP sewer certification is a process used to determine whether the existing sewer infrastructure can accommodate the stormwater and sanitary discharge associated with a proposed development.
• The NYC Department of Environmental Protection oversees the city's water and sewer infrastructure. When a project involves a new sewer connection or increases the amount of stormwater or wastewater generated on a property, sewer certification may be required.
• The certification process helps establish whether the proposed connection is appropriate for the development and whether additional drainage measures or infrastructure improvements may be necessary.
• For example, a new residential building may require a sewer connection for wastewater and stormwater. A substantial home addition could also trigger a review if the proposed work changes drainage conditions or increases the property's discharge.

According to NYC DEP, sewer certification is required for new connections to city sewers, private sewers, private drains, septic systems, or other approved outlets. It may also be required for certain alterations that increase sanitary or stormwater flow.

2. What Is the Difference Between a House Connection Proposal and a Site Connection Proposal?

• One of the most important parts of understanding NYC sewer certification is knowing which application applies to your property.
• NYC DEP uses two primary types of sewer certification applications: the House Connection Proposal (HCP) and the Site Connection Proposal (SCP).
• House Connection Proposal (HCP)
• A House Connection Proposal generally applies to qualifying one-, two-, or three-family homes that meet the city's eligibility criteria.
• The property must generally be fee-simple residential property without commercial use, have individual connections to existing sewers fronting the property, and not have common drainage facilities connected to another dwelling unit. Specific exceptions and conditions may apply.
• An HCP documents the proposed sewer connection and provides the supporting information needed for DEP certification.
• Site Connection Proposal (SCP)
• A Site Connection Proposal applies to developments that do not qualify for an HCP.
• This can include larger or more complex developments and properties with sewer arrangements that fall outside the HCP eligibility criteria.
• An SCP may require detailed site plans, sewer information, stormwater calculations, sanitary flow calculations, and supporting technical documents.
• Both application types must be prepared by or under the supervision of a New York State-licensed Professional Engineer (PE) or Registered Architect (RA).
• The appropriate application depends on the property's legal configuration, proposed development, and existing sewer conditions. Homeowners should confirm the correct filing with their design professional before submitting an application.

3. When Is DEP Sewer Certification Required?

• Not every home renovation requires sewer certification. The need for approval depends on the proposed work and the applicable NYC requirements.
• Projects that may require sewer certification include:
• New home construction: A new residential building may need certification before a new sewer connection can be approved.
• Major home additions: Enlarging a property may change roof drainage, site coverage, or wastewater demand.
• New sewer connections: Connecting a property to a city sewer or another approved outlet requires the appropriate certification and permits.
• Substantial development projects: Projects that change the site's drainage or sanitary flow may require additional review.
• Certain existing-building alterations: Some renovations that increase stormwater or sanitary discharge may trigger certification requirements.
• A standard interior renovation that does not affect sewer connections or increase relevant site flows may not require a new sewer certification.
• However, homeowners should not make this determination based on the project's appearance alone. An architect or engineer should review the scope of work and confirm the applicable filing requirements with NYC DEP and the Department of Buildings.

4. What Documents Are Needed for Sewer Certification?

• Preparing a sewer certification application requires accurate information about the property, the proposed construction, and the existing sewer infrastructure.
• The exact submission requirements depend on whether an HCP or SCP is being filed and the conditions of the site.
• Common supporting documents and information may include:
• Property tax maps and lot information
• Existing sewer maps and available as-built records
• A current property survey
• Existing and proposed site plans
• Proposed sewer connection locations
• Stormwater drainage calculations
• Sanitary flow calculations
• Details of proposed drainage or detention systems
• Additional technical documents required by DEP
• DEP explains that applicants must consult tax maps, sewer maps, and as-built sewer records when preparing HCP and SCP applications. If the relevant sewer records are unavailable or do not match actual site conditions, a field investigation may be necessary.
• Organizing these records early can help your design professional identify potential issues before submitting the application.

5. Why Stormwater Management Matters for Queens Properties

• Stormwater management is an important consideration for many residential construction projects in Queens.
• Rainwater from roofs, driveways, patios, and other hard surfaces must be managed in accordance with applicable drainage requirements.
• When a property is expanded or redeveloped, the amount of impervious surface may increase. This can change how much stormwater flows toward the sewer system.
• Depending on the project, DEP may require stormwater calculations or measures designed to control the rate at which water leaves the property.
• Potential solutions may include approved detention systems, roof detention systems, or other stormwater management measures appropriate for the site.
• The correct solution depends on the property's layout, drainage conditions, applicable requirements, and the proposed development.
• Addressing stormwater management during the design stage can help prevent costly changes later in the construction process.

6. What Happens If There Is No Sewer in Front of Your Property?

• Some Queens properties may not have an existing sewer directly fronting the property, or the available sewer records may not accurately reflect existing conditions.
• This can complicate the certification process because the proposed development still needs an acceptable method for handling sanitary wastewater and stormwater.
• Depending on the circumstances, the project may require further investigation or an alternative drainage arrangement approved by the relevant authorities.
• NYC DEP strongly recommends a pre-submittal meeting for certain complex situations, including projects without a sewer fronting the property, easement connections, detention ponds, green roofs, and master-plan applications.

7. Does Sewer Certification Mean You Can Start Connecting to the Sewer?

• No. Sewer certification and a sewer connection permit are separate steps.
• Certification addresses whether the proposed connection is acceptable from a sewer-availability standpoint. A separate DEP permit is required to authorize the actual sewer connection work.
• According to NYC DEP, a Licensed Master Plumber must apply for the appropriate sewer connection permit when required and perform the authorized work. The application may require the certified HCP or SCP, a valid DOB work permit, and other supporting documents, depending on the project. Inspection requirements also apply.
• Homeowners should coordinate these steps with their design professional and Licensed Master Plumber to ensure that the required approvals are in place before the relevant work begins.