I know this may sound like a weird question. I recently found a bottle of holy water with a bunch of religious books which are at least 30 years old. There is still water in the bottle. Is this holy water still “good”? I don’t recall reading about any statutes regarding the age of holy water. If it should be disposed of, what is the proper method of doing so?
It doesn’t expire. I would just put it in a holy water font and use it to bless myself. We have some from Rome we picked up 25 years ago. Our priest just used it to bless a new icon of St Mary of Jesus Crucified.
No, but it does evaporate. 
No, it isn’t expired. I believe the blessing of sacramentals, including holy water, remains until the object no longer appears as it is meant to. In the case of holy water, the blessing is removed if it doesn’t appear to be the liquid water that was blessed anymore, so if it evaporates or is mixed with other water or substances.
I’ve had a little bottle of Lourdes water that has lasted me for years. I never want to use it up!
I use just a very tiny amount every now and then…and I know I shouldn’t be so protective of it. I can always get Holy Water from the font at church. But this is from Lourdes!!!:)
Theologically, you know holy water is holy water regardless where it originates (the water, not the grace, I mean.) I’ve heard others suggest just add holy water from your local parish to the bottle and it will mix with the holy water from Lourdes. As long as you don’t spill the entire container, should be good for as long as you remember to “top off” the container! 
But I think the water is different since it originates from the spring that St. Bernadette dug up in accord with Our Lady’s command. As far as I know, a priest doesn’t bless the water from the spring at Lourdes so it isn’t considered holy water like the water we are sprinkled with at the Asperges me. Plus, people get cures from maladies in the Lourdes water and not parish holy water (usually). I haven’t studied Lourdes too much besides from watching a movie, so I can’t be certain.
No expiry, but there might be a “Best Used By” date.
You may be correct. I still believe holy water is holy water. If God wants to do a miracle, He certainly doesn’t need water from a specific location to work His miracle.
It does not expire because it a Church approved symbol of purification and and a prayer for God’s protection, like a cross or religious medal – there is no magical power in sacramentals.
Water doesn’t exactly spoil, but after 30+ years, I wouldn’t recommend drinking it. It should be fine for blessing though.
I am glad you asked this question because I had wondered the same thing. I have some that is at least 8 years old.
It is an evening of both interesting and relatively complex threads!
Blessings on objects do not expire and so Holy Water, once blessed, remains Holy Water just as other blessed objects remain blessed. As one commenter says, however, I would strenuously recommend not internally ingesting water that has been stagnate for that long but using it in a holy water font or for sprinkling.
Confiteor Deo is correct that Lourdes water is not the same as Holy Water…at least as it emerges from the spring at the grotto…unless the water from the grotto that has been bottled has been subsequently blessed by a priest. Then, you have both Lourdes water and Holy Water. The water from the spring at the grotto of Massabielle (Lourdes) is a special gift from Heaven since the spring was of miraculous origin, a gift of the Blessed Virgin during the course of the series of apparitions to Saint Bernadette. (There is also a spring of water associated with the approved visions of the Blessed Virgin at Banneux in Belgium with miracles associated with it, by the way. The Belgian apparitions of Beauraing and Banneux are less well known in the English speaking world.)
If it is necessary to dispose of Holy Water, as the original question asks, it should never be discarded down an ordinary drain as the water is blessed and a sacramental. Normally, at one’s parish church, holy water needing to be disposed of would be poured into the sacrarium which drains from the sacristy into the ground beneath the Church. It could, in other circumstances, be poured into a potted plant (if the quantity is small) or into the ground, such as around the foundation of your house.
Crown of Stars: you can obtain Lourdes water here in the United States through the Missionary Oblates of Mary Immaculate. This is a service that they provide at the shrines they administer and also by mail. This website will get you started: oblatemissions.org/7854/free-bottle-of-lourdes-water-when-you-present-your-needs/
You are correct: the water from the spring in Lourdes is not Holy Water unless it has been blessed by a bishop, priest or deacon. It is not systematically blessed at the shrine, that is, there is no priest standing at the fountains blessing the water as it pours forth. (I imagine, however, that any priest at the shrine would be happy to bless the water pilgrims collect from the fountains.)
The Holy Water I carry with me is water from Lourdes that I asked my pastor to bless.
You can also top up the Holy Water with tap water. As long as the original Holy water content is more than 50% then all the water is considered Holy Water.
Holy water can always be poured directly into the ground, preferably in a garden that will not be routinely trampled by pedestrians, because this is exactly the same as pouring it down a sacrarium. A sacrarium is merely a sink and drain not connected to the sewer system but draining directly into the ground below.
I would not pour it into any potted plant, as this is not equivalent to natural earth.
Unless is purified and has a residual amount of chlorine present, water that sits around for any period of time can and does carry pathogens. Under no circumstances should any one drink this water.
My husband is a manager for a rural water company. Keeping water free of the many dangerous forms of pathogens is his major concern.
I have had some holy water that has evaporated
The one time that the homeopathic principle actually works…
I have many Holy bottles off Holy water,they will evaporate in time, but I keep them until they do, and get more Holy water from church ,I do not throw it away,because it is Holy Blessed water.