You can create one dynamic configuration component which will hold all static content (like yours) specific to any web publication. For this you need to create one schema maybe with all possible fields to make it more generic and reusable. Create the component as dynamic, provide all required values and publish it to broker. Write a method to query and load the configuration related information in any object maybe, to make the performance better store it in cache/session. Good thing you don't have to modify individual items which uses the same values. This could be more effective when we have more items (alt links, any other reference etc). You can check if your design needs something like this.
Else, you can opt for the option suggested by Raj which is more effective in this particular case. You can select and provide different values if needed for the pages. You may have to modify the page metadata schema (if using one) and provide values at page levels. To avoid these, you can try giving a default value in the schema field (if the value is static and same for all).
Let me know if this helps !!
