Nitrates are toxic in very high levels, If you drink the water, its ok. This is my opinion, i have no knowledge of toxicity levels for humans or chameleons.
I would try to keep all your post regarding the same issue to the same thread, It helps keep every thing organized, and in order and the people that are helping you in those other threads will be more apt to help, because the answers to specific questions may have been answered in previous posts.
Its good that you are asking questions, as it means you care.