Cook the bacon in a large skillet over medium heat, turning as needed, until the fat has rendered and the bacon is golden and crispy, 8 to 10 minutes total. (You may need to cook the bacon in two batches, draining the rendered fat from the skillet between batches.) Let the bacon cool to room temperature, then crumble up into bite-sized pieces. Cook the pasta according to package directions. Drain, rinse with cold water, and let cool.  Meanwhile, in a large bowl, whisk together the mayonnaise, milk, ranch seasoning, lemon juice, parmesan cheese and black pepper. Add the pasta, tomatoes, lettuce, onion, herbs and half of the crumbled bacon to the bowl with the dressing. Gently fold together to coat. Top with remaining bacon and serve.