Every municipality that accepts a new sewer system into its infrastructure requires a conforming as-built package before granting final acceptance. The details vary by jurisdiction, but the core data requirements are consistent across North America. Understanding what city engineers look for -- and why -- helps contractors build the as-built during installation rather than scrambling to reconstruct it at closeout.
What does a city engineer require for sewer as-built approval?
City engineers require MH rim and invert elevations (all pipes, in and out), pipe size and material, calculated slope between manholes, depth of cover at road crossings, GPS coordinates (increasingly required), and pre-backfill photographs. Submit by the engineer of record or licensed surveyor. Review time ranges from 2-5 days (small cities) to 4-8 weeks (California).
When a city engineer accepts a sewer system, they are accepting ongoing maintenance responsibility for infrastructure that will be underground for 50-100 years. They need accurate as-built documentation to locate systems for future excavation, verify that the system was installed to perform as designed, troubleshoot operational problems, and assess whether capacity exists for future connections.
A sewer system accepted without accurate as-builts becomes a liability. When a blockage occurs at year 15, the maintenance crew needs to know where each manhole is, what the pipe slope is, and whether the invert elevations match what SCADA expects. When a parallel utility is excavated and the sewer is not where the map says it should be, emergency response costs spike dramatically. The as-built package is not paperwork for its own sake -- it is the operational record of critical infrastructure.
Municipalities that tie final acceptance and surety release to as-built approval have learned this from experience. Projects accepted without adequate records create expensive problems for the public works department years later. The contractor requirement is a risk transfer mechanism.
The following data elements are required in virtually every municipal sewer as-built acceptance review:
Invert elevation at the incoming pipe and outgoing pipe at every manhole. Must be actual field-measured elevations, not design values. The invert-in and invert-out may differ due to a manufactured drop in the manhole; both must be recorded.
Slope percentage between each manhole pair, calculated from the measured invert elevations and the horizontal distance. City engineers will not calculate this for you -- submittals without calculated slopes are rejected.
Confirmed diameter and pipe material (PVC SDR 35, HDPE, ductile iron, etc.) at each run. If the installed size or material differs from the approved drawings, flag it as a deviation.
Documented depth of cover at road crossings, at structures, and at any location where minimum cover was a design consideration. Crown elevation minus ground surface elevation.
Northing, easting, and elevation of each manhole, in the horizontal datum used by the municipality (typically NAD83 state plane). Required for GIS integration into the utility management system.
Top-of-frame elevation at each manhole. Required for hydraulic modeling, surface drainage assessment, and as a check on depth-of-cover calculations.
Any difference between the approved construction drawings and what was actually installed must be explicitly noted. Undisclosed deviations, discovered at final inspection or later, result in rejection and potential remediation requirements.
Most municipalities require the contractor's authorized representative to sign the as-built package, certifying that the data is accurate and the system was installed per approved plans (with noted deviations).
Municipal as-built format requirements have evolved significantly over the past decade. Most jurisdictions now accept -- and many prefer -- digital submittals over paper.
PDF with manhole schedule table: The most universally accepted format. The package includes a formatted manhole schedule (table of all MHs with inverts, GPS, rim elevation), a pipe run table (from/to MH, length, size, material, slope), depth-of-cover summary, and red-lined plan sheets showing any deviations. PDF submittals must be legible and include the contractor's signature block.
GIS shapefile or geodatabase: Many larger cities (and all cities building or maintaining a GIS utility layer) require a shapefile export of manhole points and pipe segments with attribute tables matching the as-built data. Coordinates must be in the correct horizontal datum and projection. Cities that require this typically provide a template or schema document.
Red-lined plan sheets: Required by most municipalities in addition to tabular data. The contractor marks up the approved construction drawings to show actual locations of manholes, actual pipe routes, and any deviations. Digital red-lines (in the original CAD or PDF format) are increasingly accepted.
Portal submittals: State DOT and large city projects increasingly route as-built submittals through project management portals (e.g., ProjectDox, eBuilder, Unifier). These portals have specific file type and naming convention requirements -- check the project closeout instructions for portal-specific requirements before submitting.
Based on common public works review patterns, the following are the most frequent reasons sewer as-builts are returned for correction:
Most municipal sewer contracts specify as-built submittal within 30 to 60 days of system completion. Final acceptance of the sewer system -- and release of the performance bond or retainage -- is conditioned on as-built approval. Projects that go to final walkthrough without an as-built package can wait weeks to months for final acceptance.
The approval cycle after submittal is typically 10-20 business days for a first review. If the submittal is rejected, the contractor must correct and resubmit, adding another review cycle. A single rejection can delay closeout by 4-6 weeks. Two rejections on a $2M sewer project holding 5% retainage means $100,000 is tied up for an additional 6-12 weeks unnecessarily.
Contractors who document as-builts during installation -- capturing invert elevations at each manhole as it is set -- consistently submit first-time-passing as-builts. The data is accurate because it was measured while the pipe was visible and accessible. Contractors who reconstruct as-builts from field notes after the trench is closed consistently make errors that require re-submittals.
City engineers require: MH-to-MH invert elevations (in and out), pipe size and material, calculated slope between each MH pair, depth of cover at road crossings, GPS coordinates of all manholes, rim elevations, and the contractor's certification signature. Deviations from approved drawings must be explicitly noted.
Most municipalities accept PDF with a formatted manhole schedule and pipe run table. Larger cities require GIS-compatible shapefile exports. Red-lined plan sheets are typically required in addition to tabular data. Large public works projects may route through portal submittal systems with specific file requirements.
Most municipalities require submittal within 30-60 days of project completion. Final acceptance and retainage release are conditioned on as-built approval. First-review turnaround is typically 10-20 business days. A rejected submittal requiring resubmission adds another 4-6 weeks to closeout.
Common rejection reasons: missing invert elevations on intermediate manholes, slope not calculated, design elevations used instead of as-built, GPS not in required datum, deviations from drawings not noted, and contractor signature missing. Sitemark's structured data entry prevents all of these omissions.
Sitemark captures every required data point at each manhole as you install, generating city-accepted as-built packages at job close without a data-entry marathon.