Hi Constable,
I grew up in Plum Borough, across the river. I could see the big red & white smokestack in Springdale from my window. I had cousins who lived in Springdale.
Good for you for jumping into improving your chicken laws!!
Overall, I think your number one thing is that you need to make it "safe" for them to say yes. Consider what this means... not sticking their necks out. They will be sticking their necks out less if they know about other places, similar to Springdale, where this has worked.
I have a couple questions for you.
Why is this going up to the council? Did the code enforcement officer have an opinion or "ruling"? Are they going to have any staff give their opinions about it? If the staff is going to recommend against, you have an uphill battle. Do you know any members of the city council well enough to broach this in advance of the meeting, to get their read on it? Or if the council is representing certain areas of town, call the one who is in your area, to let them know that this issue is coming before them, briefly explain the concept, and ask if they have any advice for you before you take it before the full council. Asking any elected official for "their advice" is usually helpful to getting some useful information. If they are dead opposed, you will learn that. If they are sympathetic, you may get a good inside scoop.
If you had a good rapport with the code person, you might ask what their opinion is of the matter, see if you can know whether you will have to overcome staff opposition? Ask the staffer if he or she will be at the meeting, or who else might speak to this issue there?
Make it safe for them to say yes. Let them know that this is not a radical idea, and that you are not the only person who has thought of this!
You might want to incorporate into your letter a list of places where chickens are currently permitted, that are similar in population density and community mores as Springdale. (or maybe just one tiny notch more "upscale" -- a community that Springdale might look up to? ) I don't really know what Springdale is like as a community, but you could describe it on here, and some people might be able to give you examples of similar towns where chickens are permitted. Even better if chickens are permitted in other similar towns in the Pittsburgh area.
Something like "Across the country, urban and suburban areas are allowing small backyard chicken flocks. Some examples of cities that allow chickens, include Portland Oregon -- (see list on thecitychicken.com
http://home.centurytel.net/thecitychicken/chickenlaws.html )
Have you talked to your neighbors? If you can stand up in the meeting and say that you've talked to your neighbors, and they don't have objections, or that they are willing to let you try the idea, then that strengthens your case. If you have a neighbor who is opposed, quite honestly I think you should tell the neighbor about the meeting, and offer to discuss his or her concerns in advance. If the neighbor comes to the meeting, you should be prepared to know what he or she - or any other opposing neighbors - would say, and be prepared to politely listen to and tactfully counter their concerns.
Do you know any other folks in Springdale who are chicken-interested? If so, take them to the meeting! It is much much better to show up as even 3-4 households, than as just one. I'd ask around through any social networks you have - school, church, soccer group, whatever. See if anyone else is interested in keeping chickens, and ask them to come to the meeting with you. They don't have to speak, except briefly to introduce themselves. They can say "I'm interested in the idea of keeping chickens" but they wouldn't have to commit to it or stick their necks out. Additional warm (human) bodies with you at this meeting will help. The more the better.
I would also suggest to take in photocopies of 1-2 articles in VERY mainstream media talking about backyard chickens. I think Backyard chickens was recently in USA Today, and there was also an article in Newsweek in November. Even better if there's an example from the Pittsburgh Post-Gazette - in which case I would take 1 national and 1 from the PG.
Take a small packet including copies of your letter, a list of a few cities and a few more suburban areas - nationally and locally - that allow chickens (NOTE that the list on the website above also includes places that do not allow chickens, so do not just cut and paste. Be selective.), and these news clips.
Take enough copies for the number of council members, plus enough for any friends you have recruited to the meeting, a few in case there are folks opposed, and perhaps 5-6 for staffers. Sometimes one copy needs to go into the official record.
Consider what will happen if they say "no". My suggestion is, if they say "no" to chickens under the current pets ordinance, to ask them to consider writing a poultry-specific ordinance, and ask the code enforcement (or other staffer) for their help with this.
Also, if they say no, you could consider asking for their advice as to whether you could seek a variance from the current ordinance on perhaps a "trial" basis. You would probably work with the code enforcement officer, or another staffer, on the details.. Consider what other options the council might have that would be acceptable to you, but less than what you ideally want (= blanket permission under the current ordinance without a whole lot of run-around!).
Hope this helps. I'm sure others on here will be very helpful, too. Now, wish me luck with my local planning commission tomorrow night for some bicycle infrastructure improvements!