Iron sediments from rusty pipes are not likely to cause health problems. While a glass of yellow-hued water is off-putting, it is generally safe to drink yellow water in the short term. But you certainly want to address this problem. In the meantime, switching to bottled water until the yellow water issue is resolved is a good idea. 

If the lead paint is in a place that is not easily disturbed and is not flaking or deteriorating, you do not necessarily need to remove it. Lead is toxic when dust particles or flakes from peeling lead paint are ingested. If people are not in the area with the lead paint, it may be safe to leave it in place. You still may want to consider encapsulation with a paint formulated for covering lead-based paint, just for an added layer of protection.

According to the Environmental Protection Agency (EPA), hazardous waste is generally classified into four main categories:

1. Characteristic Wastes: These exhibit at least one of four hazardous traits: ignitability (flammable, like gasoline), corrosivity (can rust or decompose materials, like car batteries), reactivity (unstable and can explode, like aerosol cans), or toxicity (harmful when ingested, like lead-based paint).

2. Listed Wastes: These are specific wastes from manufacturing and industrial processes that the EPA has officially designated as hazardous. They include byproducts from processes that use solvents, pesticides, and other chemicals.

3. Universal Wastes: These are commonly generated hazardous items that are subject to streamlined regulations. Examples include batteries, pesticides, mercury-containing equipment (e.g., bulbs), and some lamps.

4. Mixed Wastes: This category includes waste that contains both hazardous and radioactive components, making it subject to regulation by both the EPA and the Nuclear Regulatory Commission.

DIY lead testing kits are available, but they often lack the accuracy and reliability of professional services. Professional testing is recommended for more accurate results, as properly certified testers can provide a thorough analysis, clear recommendations, and the necessary legal documentation if remediation is required.