Additional Information: Soil and Water
Previously in this blog, we’ve mentioned the City of Philadelphia’s requests for additional information. Since we see a lot of these, we are going to create a catalogue of the requests as a reference guide. We hope that this will help our clients, design partners, and contractors better understand what information is most commonly missing from an application. (If you haven’t seen it before, it’s also worth checking out the City’s list of top ten building permit application deficiencies.)
Today, we’re going to look at another subset of these cases: soil and water reports.
What’s in the ground?
Before you build in Philadelphia, the City wants to know that the ground under and around your construction site is safe. It would be pretty terrible, in the view of the City, for your brand-new development to sink into mud, or flood instantly (more on flooding in a second).
How do they test this? Well, they don’t: You hire a civil engineer to do it. The engineer takes samples of the dirt, stone, and whatever, and explains what the ground around your project is made of. They tie the whole thing up in a soils investigation report.
You probably think, “Well, that’s easy enough; and shouldn’t the engineer know to do that?” But zoning and permitting in Philly is a lot of that: things that seem simple enough that, when compounded, become difficult to remember. You’re likely to get a request for additional information if you ever try to submit a building permit application without the soil investigation report. And the architect or engineer, focused on the design of their work, may forget this important piece of information (it’s handy, of course, to have the Philadelphia Zoning team vet your application before we send it to the City).
After the soils investigation report, there may be some other information you need to offer. The City doesn’t really list this anywhere in their resources, but if you apply for new construction on a steep slope, they will require a topographical survey. The survey, like the soil investigation, is done by your engineer. You will also likely be asked to submit your plans to the City Planning Commission (CPC). The CPC is a different reviewing body than Licenses and Inspections but located in the same building.
Doesn’t Hold Water
Great news! Your soil report indicates you have a suitable composition for your building. But wait, you’re not done yet. Now you have to prove to the City that your new building won’t flood.
How do you do this? Once again: hire a good engineer! They’ll create plans that you can submit for review by the Philadelphia Water Department. If your construction is in a dangerous flood zone, the engineer can also put together a Flood Protection Information form.
There’s a little work you and/or your engineer can do to figure out if you’ll need all of this.
First, figure out if your property is in the Wissahickon watershed. You can do this by simply checking up on PWD’s “find your watershed” tool. If your property is in the floodplain, then you’ll have to submit your plans to the City Planning Commission. There’s a good chance you’ll need the Flood Protection Information form, too, at that point.
Your contractor might need to work with the Water Department as well, even if the construction isn’t in a floodplain. All construction sites are required to put erosion and sediment (E&S) controls in place. For smaller developments, this responsibility will fall to the contractor on site; with little or no oversight from the City. But if the project is more complex, and disrupts more ground area, then the contractor will need to submit an E&S plan to the right office. PWD created a very useful handout to let you know exactly when you need to talk to the City about your E&S plans.
If you happen to have $600 burning a hole in your pocket, then you can also collect some documents for the PWD to review your proposed construction. The form you collect is called an Existing Resources and Site Analysis (ERSA) application. The PWD Stormwater Plan Review website has this form and a lot of other related and useful information (including resources for contractors worried about erosion and sediment controls).
As always, though, the best way through this maze is to hire a good guide: if your engineer knows what they’re doing, they’ll be able to quickly determine whether or not your project will need special flood protection or unique construction methods because of a given soil type.